


Pressure

by TheManicMagician



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Emotional/Psychological Abuse, Gen, Physical Abuse, Underfell, pls don't hate the papaya
Language: English
Status: Completed
Published: 2016-01-27
Updated: 2016-04-09
Packaged: 2018-05-16 15:34:38
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 6
Words: 32,392
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5831092
Author URL: https://archiveofourown.org/users/TheManicMagician/pseuds/TheManicMagician
Summary: <blockquote class="userstuff">
              <p>After violently lashing out, Sans scrambles to amend his mistake.</p>
            </blockquote>





	1. Pecking Order

**Author's Note:**

> This fic takes place in the Underfell! AU. Since the rules of this AU are so loosely defined, here is my take on the world:
> 
> -Monsters live in a "dog eat dog" type of society, and won't hesitate to kill others to get what they want
> 
> -Sans is a nervous mess constantly berated by his asshole brother
> 
> -Everyone wears dark and edgy clothing
> 
> Without further ado, here we go!

Snow crunches under his boots as Sans stomps away from his sentry station. Smothering a yawn, he turns a corner. At least once he gets home he can slip in a few quick z’s before his next shift.

His mundane thoughts screech to a halt as he spots the commotion ahead. Two guards of the canine unit—it’s hard to tell who, from this distance—snap and snarl as they try to tear pieces out of each other. Sans scuttles off the path, into the safety of the trees. He edges closer so he can get a better view of the altercation.

It’s Greater Dog and Doggo, and the former seems to be at an advantage. Doggo usually has better success when attacking moving monsters, but Greater Dog is savage, not allowing Doggo a second to move in closer retaliate. White foam drips off their mouths, lips curled back into snarls that reveal glinting teeth.

Sans’ soul pounds in his chest. What is going on? Infighting isn’t uncommon, but both monsters are going for the kill.

Frustrated and panicking, Doggo hurls one of his knives at Greater Dog; it bounces harmlessly off his armor. Stupid, stupid. Why would Doggo ever challenge his superior, most especially with the scales tipped so heavily against him? If he wanted to usurp Greater Dog, why not wait until he was at rest, with his armor stripped away?

Greater Dog abruptly freezes. Doggo flinches, unable to see his enemy, and starts hastily backing away—but it’s not enough. Greater Dog seizes his moment of confusion and disorientation and darts forward, skewering the monster through the chest.

Doggo yips, claws pawing uselessly against the weapon. Greater Dog roughly tosses him to the ground. Doggo spasms as his lifeblood and magic darken the snow.

Not placated just yet, Greater Dog stoops down and rips out Doggo’s throat.

“Holy _fuck_.” Sans shudders, averting his gaze until the squelching noises taper off.

When he summons the willpower to look back at the scene, Greater Dog is standing again, nose twitching. Then he turns to look directly at Sans, white muzzle matted with blood.

Sans screams at his body to move, summon magic, do _anything_ , but he just stands there, paralyzed by fear and indecision, as the hulking form of Greater Dog lumbers towards him.

A wall of bones sprouts up between them, humming with a magic familiar but not his own. Papyrus steps forward, in front of Sans.

“B-Boss.” A flood of gratefulness washes through him.

Greater Dog’s tail tucks between his legs. Whimpering, he tries to flee. Papyrus raises his hand, and three more walls rise up, forming a fence, keeping the monster caged inside. Papyrus glances back at his brother.

“Really, Sans? You can’t even defend yourself against _Greater Dog_? Do you expect me to do _everything_?”

Greater Dog whines. Papyrus glances at him, and he quiets. He returns his attention to Sans, who has started to crack his knuckles anxiously.

“Well? I’m waiting on an explanation, here.”

There’s nothing he can say to justify himself. He was caught off-guard, and if not for Papyrus, he’d be dead right now, plain and simple.

“I—I just didn’t understand why they were fighting to kill.”

Greater Dog starts whining again, and Papyrus’ fist twitches.

“You don’t know.” Papyrus pinches the small strip of bone between his eye sockets. “Of course you don’t. Why am I not surprised?”

“Just tell me what’s going on already.” Sans snaps, nerved frayed. At Papyrus’ baleful look, he ducks his head. “Please. Boss.”

“Captain Undyne posted a missive in the town square this morning. She declared that all monsters—oh, enough already.”

Tired of Greater Dog’s muffled cries, Papyrus flicks his hand; beneath Greater Dog’s feet, more bones burst from the ground. The monster’s howls of pain die swiftly, and Greater Dog dissolves into dust, his armor falling into the snow.

“As I was saying. The captain feels the guard has become complacent. She plans to restructure the organization and reissue rankings at the end of the week, based upon our performances.”

Dread squeezes Sans’ chest. “And someone can’t be ranked higher than you if they’re dead.”

“Precisely. Let the weak tear each other to shreds. I don’t need to waste my time; none of them will dare attack me.” Sans wisely doesn’t comment on Greater Dog, the scent of his dust thick in the air.

“So you think after this week, you’ll be Captain Undyne’s second-in-command?”

“I don’t _think_ it.” Papyrus corrects him sharply. “That is simply what’s going to happen.”

Sans nods along in emphatic agreement.

“Of course. Y-You’re so cool, Boss.”

Papyrus kicks at the churned-up snow, then stares out at the horizon distastefully.

“I’ve grown weary of this backwater town. It reeks of wet dog. I’m getting that promotion, and we’re moving to Hotland.” He taps Sans’ sternum, hard enough to make him stumble back half a step. “And I can’t have you holding me back. That means I’m going to start training you, starting right now.”

Sans nods obediently. It’s easier.

Papyrus turns and starts walking without a further word. Sans scrambles to catch up to him. Papyrus prefers him to match his stride, even though his steps are sizably larger. If he lags behind, he’s berated for laziness; if he ever accidentally walks ahead, he’s accused of trying to rob Papyrus of his rightful attention.

Once they’re far enough away from the dead monsters that their dust doesn’t smell up the air, Papyrus stops. He gestures towards Sans.

“Summon your Gaster Blasters.”

As usual, Papyrus doesn’t waste any time with niceties or small talk. Sans calls forth his four blasters, directing them to rest in the snow in front of him in a neat line. Papyrus scrutinizes each of them for imperfections like a jeweler inspects a gemstone. Sans resists the urge to crack his knuckles—he knows how Papyrus hates the noise.

After a handful of agonizing minutes, Papyrus steps to the side.

“They’ll do. Fire them.”

Taking a deep breath, Sans raises the blasters in the air, in a vague square pattern. Their jaws hinge open, magical energy gushing forth. The trees in their line of attack are snapped back, some even obliterated entirely. The layer of snow evaporates entirely, revealing the brown grass and choppy mud hidden beneath.

At last the beam tapers off. Sans can hear trees cracking and collapsing in the distance. Papyrus folds his arms, looking impassive.

“Again.”

The blasters fire off again, on cue. It’s starting to tug on his internal magic now, but he can keep going. The blasters aren’t meant for consecutive attacks like this, but it’s okay. He can keep going in bursts, even with all four of them.

“Now. Let’s try something a little different. Fire them all, and don’t let the blasts end until I give the word.” When Sans gapes at him, not responding immediately, anger flashes over his face. “Understood?”

“They’re not meant for—”

 “Is. That. Understood?”

 “…Yes, Boss.”

Gritting his teeth, Sans fires the blasters again, but only pours in half the usual magical energy. This way, he’ll be able to increase the duration without the exercise taxing him so swiftly—

“Sans. Full power.”

Of course, Papyrus catches on almost instantaneously. He can never get anything past him Sans pushes the correct amount of power into the attacks. Sweat beads on his skull. 10 seconds. 20 seconds. Papyrus’ face betrays nothing as he stares up at the blasters. 30 seconds. Sans starts to gasp for breath.

“Boss—” He pleads.

“Keep going.”

40 seconds. One of the beams dips in power. Panicking, Sans throws more than enough energy back into it to boost its output back up. His eyes dart over to look at his brother, but either Papyrus didn’t notice the slip or is deciding to allow it.

50 seconds. Black spots dance into his vision—he doesn’t think he’s breathing, anymore—but he keeps the attack going. His soul _screams_ inside his chest, but he keeps the attack going.

60 seconds.

“Stop.”

The Gaster Blasters shatter to bits before they hit the ground. Sans collapses in the snow, shaking. He rubs at his chest, mentally begs for his soul to keep itself together and not shatter, too.

Papyrus looms over him.

“One minute. That’s how long you can hold an attack for? One measly minute?”

Sans turns his head slightly to the side and vomits. Papyrus pulls a face.

“I see even something this simple exhausts you. I’ll have to start even simpler.”

“S-Sorry.”

Papyrus turns away. Sans doesn’t blame him; he’s in a sweaty heap in the snow, his puke trickling down the snow and touching his cheek.

“I’ll accept your apology if you reach your sentry station on time. And if I find you asleep on the job…” He lets the rest of his threat hang between them as he marches away to attend to his other duties.

Laboriously, Sans heaves himself into a sitting position. He cleans his face with with the sleeve of his hoodie, before removing his phone from his pocket with fumbling fingers to check the time. He has half an hour until his next shift. Papyrus had volunteered them both for extra shifts a few months ago in the hopes of impressing the captain; so far, it’s only served to make Sans more exhausted.

Sans slowly stands up, using a nearby tree for balance. After he takes a moment to gather himself, he pushes off the tree, takes a step forward, but he immediately buckles, falling face-down into the snow.

He groans. His soul throbs. He just wants to sleep.

But Sans picks himself back up again, and starts staggering back towards the road. He’s safe from attack if he can just make it to the sentry station. Backstabbing is perfectly acceptable as long as it’s done on your own time. Some measure of stability has to be preserved, and sentry duty is highly esteemed, despite its rather mundane nature. Every monster wants to be the one to catch the final human, to wrench out their soul and subject monsterkind to their will.

Sans slumps with relief as he reaches his sentry station and sags into his seat. A few scattered mustard packets litter the table. The skeleton tears them open greedily, licking up their meager, near-frozen contents. They give his magic the slightest of boosts, but it’s better than nothing. He’ll have to wait until the end of his shift to replenish his magical reserves.

Sans pillows his head in his hands, then jerks up into a proper upright posture again. He mustn’t fall asleep. Even if Papyrus’ threat is empty, there’s always the slight chance that it’s not.

Every monster wants the final human’s soul for themselves. Sans is one of the few exceptions. All that power at his disposability would be too much responsibility for him. He doesn’t want to rule over anyone. Not to mention, Papyrus would be shattered…

It seems Papyrus’ goal has shifted slightly, however. Once they left New Home, Papyrus pulled all kinds of strings—and killed all kinds of monsters—to get them a home in Snowdin. After all, if a human survived the Ruins, the small settlement in the woods would be their next stop. So why does Papyrus covet the position of second-in-command, of a station in Hotland, all of a sudden? Could he be planning to cozy up to Captain Undyne through his newfound status, then kill her? Or, perhaps, something more sinister—Hotland is home to Alphys, after all. Cruel jokes have trickled down through the ranks about the Royal Scientist’s relationship with the captain. Maybe Papyrus is planning to use her as leverage against Captain Undyne?

“What are you up to, bro?” He wonders softly to himself. They used to be more of a team, back when they were younger. What the hell happened between them?

A sudden noise startles him. Magic sparks on his fingertips for a second, then sputters out again. He’ll stand less of a chance in a fight than ever. He looks around wildly—then slumps with relief when he spots the source of the sound. A clump of snow had fallen off a branch, nothing more.

Sans’ sentry shift passes as an exercise in endurance; he grapples both with the tedium of his work and the exhaustion in his bones, determined not to doze off.

When his shift ends, to his surprise, Papyrus comes to retrieve him. His shock must show on his face, because Papyrus raises an eyebrow.

“Is there a problem?”

“No p-problem here.”

He walks with Papyrus back into town, resisting the urge to look over his shoulder. If anyone wants to take him out, they’ll have to get through Papyrus, first.

To his puzzlement, rather than heading straight home, Papyrus turns prematurely, to enter Grillby’s. Sans hesitates. Papyrus loathes the bar. That’s why Sans always has to sneak out to it—though he suspects the scent of beer and cheap food clings, and Papyrus can always smell the truth on him when he stumbles home in the early morning.

“Keep up,” Says Papyrus. “I don’t want to be in this disgusting place any longer than is necessary.”

Papyrus enters the bar, Sans following close behind. All eyes turn to look at them, most of them unfriendly. The regulars, who always harangue Sans when he comes in alone, are silent, but their eyes glitter with malice. What remains of the canine unit sits at another table. They growl lowly under their breaths. They probably think Papyrus killed Doggo and Greater Dog, just because he felt like it; the tall skeleton doesn’t bother to correct their assumptions. The tune on the jukebox ends, and no one gets up to restart it again, sitting in tense silence.

Papyrus stalks right up to the bar counter. Grillby sets aside the glass he was polishing, and nods at the order Papyrus rattles off. He disappears immediately into the kitchen to prepare the food; unlike Sans, his brother is impatient. Grillby is one of the few monsters Sans has never seen in action. The fire monster has the rare talent to stay neutral in all of Snowdin’s disputes, without seeming like he’s too good for them and pissing everyone off.

Papyrus idly taps his fingers against the bar counter, in a position as relaxed as someone like him can be. Even after all this time, it still baffles him. If all these monsters attacked at once, there’s a chance they could take Papyrus down. At the very least, they could wound him; and down here, wounds are as good as a death sentence. You don’t get the time needed to recover; someone always manages to kill you before then.

So how is Papyrus always so god-damn calm? So confident? They’ve been in here a total of five minutes, at best, and Sans’ knees feel weak. He wants to run. He cracks his knuckles as quietly as he can.

To his relief, Grillby reappears soon enough, holding out a brown paper bag, already mottled with grease from its contents. The fire monster knows better than to ask for payment.

“It’s yours.”

It takes a moment for Sans to realize Papyrus is talking to him. He snatches up the bag before his brother changes his mind about this whole thing.

Once the door to Grillby’s shuts behind them again, Sans can’t help but sigh in relief. Papyrus rolls his eyes.

They reach home, and Papyrus opens the door. He doesn’t bother with a lock; no one will dare vandalize his property.

Sans summons some scraps of courage from the familiar, safe surroundings.

“Um…why did you get me food from Grillby’s?”

Papyrus turns back to look at him.

“Not that I’m not grateful. I am. I was just…wondering.” He tries his best not to fidget under his brother's stare.

“You don’t really deserve it after that pitiful display this afternoon.” Papyrus confirms. “But you’re no good to me if you’re too weak to do anything.”

“T-Thank you.”

“Save it.” Papyrus stomps up to his room, closing his door definitively behind him. He expects to be left alone for the rest of the night.

With his brother gone, so is any of Sans’ decorum. He tears into the meal; two burgers, with a hearty side of fries. He smiles slightly as he bites into the first burger; it’s slathered in mustard. Papyrus won’t touch the stuff, but it’s Sans’ favorite. He’ll have to thank Grillby the next time he sees him.

Sans polishes the meal off in record time, his soul thrumming happily as his magic starts to elevate to safer levels. He then fastidiously cleans off the living room table; if Papyrus finds so much as a speck of salt left behind, he’ll have his head.

Sans climbs the steps upstairs slowly, looking forward to spending some quality time with his mattress. He hesitates in front of Papyrus’ closed door. Days like today make him hope that somehow, buried under his layers of pride and anger, Papyrus cares for him. He quashes down the hope. Monsters do not love.

~*~

A pair of hands latches onto his ankles. His magic instinctively flares to life, but he stuffs it back down as he realizes who it is. Papyrus finishes dragging him out of bed until he hits the floor, skull smacking painfully against the hardwood.

“Boss, what the hell—”

“You can no longer afford to take such long naps. I only have six days left to whip you into shape. We’re training, now.”

Sans rolls so he can see the window; it’s still pitch black out, the magically generated sun still absent. Far too early for any sane monster to be up and about.

“Boss, I promise I’ll be ten times more efficient if you let me sleep just one more hour—”

“Nonsense.” Papyrus grabs him by the front of his shirt, tugging him up into a standing position. “I’ve only had three hours of rest and look at me.”

Well, he tried. He certainly didn’t expect Papyrus to acquiesce to his request. The best he can hope for now is his brother’s newfound training mania only lasts until Captain Undyne re-ranks the Royal Guard, and doesn’t extend any further.

He shrugs on his black jacket, crams his feet into his boots, and is ready to go.

As Papyrus leads him out of town, uncertainty and anxiety begin to swirl within him. What kind of training will his brother put him through today? Will he make him use his Gaster Blasters again? What if he can’t keep them going for a minute again? Oh God, what if he can’t even manage 30 seconds? His forehead grows clammy with nervous sweat. His nervousness builds and builds. By the time they reach the forest, he has to clench his hands into fists to hide their trembling.

Papyrus folds his arms. “We’re going to try something different today.”

His statement somehow both quells Sans’ anxiety and reignites it again. He’s glad he won’t have to suffer through the Gaster Blaster exercise again, but what will it be instead?

“It’s clear from yesterday that I don’t have a firm grasp on the limit and range of your powers.” Papyrus spreads his arms wide in invitation. “So I want you to attack me so I can see how you fight.”

No no no. “Boss, I don’t—”

“What? Don’t want to hurt me?” Papyrus snorts. “I doubt you’ll land a single blow.”

Still, Sans hesitates to call upon his magic. He knows he’s not as strong as his brother, that he’d never be able to hurt him, not really. But still. But _still_.

“Don’t keep me waiting. Attack.”

Sans’ eye flickers a smoking red. He raises a wall of bones, slow and easily overcome.

Papyrus dodges. With a snap of his fingers, one of his Gaster Blasters pops into existence.

“Every time you fail to come at me seriously—”

Sans is forced to teleport several feet back, lest the unleashed beam blast him to dust. The ground smokes slightly.

“—I will be forced to come at you seriously. And how long do you think you’ll last? After all, it’ll only take one hit, Mr. 1 HP.”

Papyrus is goading him to attack. Fine, then. If that’s what he wants.

Sans strikes with a flurry of bone attacks, none of the patterns similar, forcing his brother to almost dance about, moving constantly to avoid being impaled.

“Yes!” Papyrus screams, as an attack nearly severs his arm off. “Yes, yes, yes!”

Sans can feel his brother’s soul, strong and beating in his chest. He makes a cradling motion with his left hand, and he can see Papyrus’ soul shine blue, even beneath the confines of his armor.

He brings his hand down, slamming Papyrus into the ground. A flicker of pride runs through him. Papyrus is never able to turn his enemies blue without using blue attacks first, to subtly alter the composition of their souls, so they’re more susceptible to blue. Sans has no such handicap.

They continue for several minutes in this fashion, Sans tossing his brother’s body around like a ragdoll, occasionally throwing bone attacks into the mix, forcing Papyrus to both dodge and combat the effects of altered gravity simultaneously. All his sparring sessions with Captain Undyne are definitely paying off; true to his boast, Papyrus has not been hit a single time.

To catch his breath for a moment, and out of curiosity, he checks his brother’s stats.

PAPYRUS LV 15 HP 6800 AT 50 DF 50

“Holy shit,” He breathes. He knew Papyrus was strong, growing stronger all the time, but this, but _this_ —he might actually defeat them all one day. The king is the only monster to ever reach 20, the LV cap. He’s unsure of Captain Undyne’s LV, but it can’t be higher than 17.

His magic fizzles to nothing. Papyrus strides towards him, frowning.

“What is the problem? You were performing…adequately.”

“Why do you even bother with me?” Papyrus is surprised, a look seldom seen. “I mean, you’re, you’re so—” He gestures to Papyrus, not knowing how to describe it himself, but sure Papyrus understands. “—and I’m just—just—Mr. 1 HP.” He finishes lamely.

Papyrus stares at him a moment, then smacks him with an open palm across the skull.

“Ow!” He rubs at the spot. That smarts. “What was that for?”

“You’re being stupid. Am I the sentimental type?”

“…No.”

“Then you know I wouldn’t keep you around simply because we are brothers.” Papyrus doesn’t look Sans in the eye. “You have some value to me.”

Sans soaks up the rare praise, soul pulsing with a faint joy.

“Now stop slacking off and fight!”

~*~

Three days left until Captain Undyne’s reevaluation. Like the past three mornings, Sans trudges beside Papyrus until they’re past the borders of Snowdin, where they can spar free of potential distractions. As Papyrus pulls him into battle, Sans struggles to remain upright, head swimming. Papyrus’ words did well to motivate him, at first, and he attacked with vigor and finesse.

But his energy fizzled down to nothing soon enough. It’s basic mathematics, addition and subtraction. Every day he subtracted more and more of his magical energy, as Papyrus demanded increasingly complex maneuvers of him. And every day, he added less and less to his reserves, as even his favorite foods left him feeling queasy. Sans was just able to choke down his meal last night; honestly, he’s not sure if he can manage anything today.

“Let’s just get right to the point.” He mutters.

He summons two of his Gaster Blasters, and they hound Papyrus. Sans can’t have them constantly emitting blasts. The pain would be unimaginable. So instead, he uses the threat of what they can do against Papyrus, shoving their muzzles threateningly in Papyrus’ face. Not knowing whether they’ll fire or not, Papyrus is forced to dodge either way.

“Papyrus, sir!” Whimsalot flutters towards them.

Sans dispels his magic instantly. He could almost kiss the monster for the distraction. He leans back against a nearby tree, catching his breath.

Whimsalot salutes, hovering in the air before Papyrus.

“What is it?” The tall skeleton is disgruntled at being interrupted.

“The Captain requests your presence for a training session immediately.”

Papyrus lets out a satisfied hiss.

“Let her know I’ll be along shortly.”

“Yes, sir!” Saluting one final time, Whimsalot darts away.

Papyrus looks like a cat who just devoured a canary.

“This is perfect. I’ll use this sparring sessions to demonstrate that I’m the only one worthy of the second-in-command position.”

“G-Good job, Boss.”

Papyrus frowns. “You should be more enthusiastic. This means you get a break for today.”

Sans tries to smile, but can only manage a grimace.

They walk home. Papyrus lingers just long enough to give himself a once-over in the mirror and then he’s gone, unwilling to keep the captain waiting for him for long.

Sans curls up miserably on the couch. He should use this blessing of extra time to his advantage. He should go to Grillby’s, and gorge himself to replenish his magical energy as much as possible before Papyrus returns. But he can’t eat. He feels nauseous just considering the prospect of food.

He hugs himself, bones shaking with weariness and fear. He can’t keep doing this. It’s killing him. Tears bud in the corners of his eye sockets, and he can’t help but erupt into a fit of crazed giggles and snorts. He thought all his tears were beaten out of him, long ago. Guess that’s one more thing he’s wrong about.

Sans contemplates just leaving. Just warping right out of Snowdin, to wherever the fuck he wants. Papyrus would come home, ready to berate and chastise him, to find only an empty house waiting. He chuckles, imagining the stunned, frazzled look on his brother’s face if he simply vanished. What would Papyrus even do after that? God knows he couldn’t go a day without nagging someone about something. Maybe he’d take in one of the dogs—seeing as the canine unit is crumbling to pieces—and dress it in one of Sans’ spare hoodies. Sans laughs and laughs, until his laughter finally dies.

Sans could leave right now.

But…he can’t. Where would he go? The rest of the underground is small and cramped; at least in Snowdin, he can breathe in the scent of the pine trees. New Home always stank of blood and dust and piss.

And even if he found a place to settle down, he’d never be safe. Anywhere he went, someone would check his stats, and they’d know he’s just free EXP waiting to be claimed. He can’t do it. He can’t leave. Safety is with Papyrus.

But. It hurts. It’s only been a few days, but the few snatches of sleep and bites of food he’s managed aren’t enough to sustain the energy he’s being forced to expel.

“Just three days left.” He whispers, but the words feel like a false promise even to him. “Just three days left.”

~*~

“Sans! Get up!” He awakens some time later to Papyrus barking in his ear.

Sans scrambles to sit upright on the couch, wiping his drool away on the corner of his sleeve. Papyrus looks dirtier than usual, as if he’s fallen in the mud a few times, but otherwise no worse for wear.

“How was the captain?”

Papyrus scowls. Oh no. It must not have gone well. What was he thinking, he shouldn’t have asked—

“Since you missed out on your training this morning, we’re making up for lost time now.”

He grabs Sans’ wrist in a grip that would bruise if he had skin. He hauls Sans after him through the town. Sans stumbles to keep pace, his head muzzy. The rest had done him a little good, but not much.

The sun hangs low in the sky, casting the town in golds and reds.

Papyrus hauls him to the same clearing they were in that morning, then releases his grip. Sans pitches forward on his hands and knees, unable to stand on his own.

“Summon your blasters.”

Sans pants with fatigue, but obeys. He calls up all four. He can’t handle it; one of them dissolves instantly after forming.

“Boss, please. I’m so tired.” His voice cracks.

“You can rest later. Right now, I’m telling you to attack. Now do it!”

One of the blasters half-heartedly lunges at him, massive jaws snapping at his armor. Sans can’t summon the energy to actually fire with it.

“Now what did I say?”

Papyrus spears the Gaster Blaster with a bone attack, cracking the skull. Sans cries out, feeling its pain through the tether. He hastily recalls the blaster. Two remain, hanging over his head.

“Attack for real, or I’ll retaliate.”

“N-No.” He tries to spare Papyrus. His brother doesn’t permit it.

“No? Did _you_ just say no to _me_?”

Papyrus steps closer, approaching. Another Gaster Blaster falls apart, Sans unable to sustain it. The final blaster starts dripping apart, losing its consistency. Sans suddenly feels as if something has knocked loose in his chest, and everything he’s been bottling up rushes forth.

“I can’t do this any longer. I can’t. I’m trying, I’m trying so hard for you, but I can’t, I _can’t_ do it anymore.”

Papyrus steps closer. A whine builds in the back of Sans’ throat, and he’s echoed by the Gaster Blaster above.

“Sans—”

“I want to stop.”

Papyrus is right in front of him. His soul lurches with primal fear.

“Just stop it, stop, _stop_!”

Papyrus reaches out a hand—to harm, to heal, Sans does not know—but his movement is seen as threatening and the Gaster Blaster opens its maw wide, and Sans’ world whites out for a moment.

When his vision clears, Papyrus is sprawled out on his back, eye sockets vacant, the breastplate of his armor obliterated, his ribs cracking into dust.

“ _Papyrus_!”


	2. Promotion

For one horrible moment, he feels relieved.

And then the panic floods in.

“Shit, shit, Papyrus—”

Sans kneels down in the snow beside his brother. He’s afraid to touch him, watching helplessly as his ribs finish crumbling into dust. But when the rest of his body fails to follow suit, Sans checks Papyrus’ HP: 120/6800.

“Still alive,” The words tumble free from his mouth, incredulous and hopeful. “He’s still alive.”

There’s still time to fix this awful mistake, if he hurries. Gingerly, he takes Papyrus’ arms, slinging them over his shoulders. He shudders as he feels Papyrus’ backbone brush against the back of his jacket, instead of the ribcage that’s supposed to be there. The husk of his armor drops off, still slightly smoking. Sans leaves it.

Papyrus’ legs drag as Sans starts walking, but there’s nothing he can do about it. He’s not used to such deathly quiet when around Papyrus; he’s always yelling or complaining about something. This vacuum of sound is uncanny.

Sans hesitates as he reaches the border of Snowdin. He can’t very well just stroll into town like this, displaying to all that Papyrus—and thus Sans—is completely vulnerable. So he skulks through backyards. His eyes are fixed on the windows, but no monsters are peering down at him.

There is a spot of luck in all this. Night has fallen. Everyone is either in their homes, at their sentry posts, or in Grilby’s. No one should spot them, but still unease clings tightly to his bones until he reaches their home.

Sans carefully sets Papyrus on the couch. He swallows, ghosting a hand over the empty space where his ribs should be. The sight of the damaged area makes him ill, so he tucks a blanket around his brother, up to his chin.

Sans leans back on his haunches with a small sigh. Like this, he can almost pretend Papyrus is asleep.

He shakes his head. This is no time for illusions. Papyrus’ HP is holding steady for now, but who knows how long that’ll last. Even if he had the magic to spare, Sans is utterly useless when it comes to healing magic. His limited possibilities race through his mind, and he ultimately settles on _her_.

But he can’t leave his brother without any sort of defense, not even for a moment. His magic actively resists when he tries to call it forward, but he’s persistent, crafting a box of bones to encompass Papyrus and the couch. It’s literally the very last bit of magic within him; not enough remains to even keep his eye flaring red. Ah well. He always felt the empty pits were far more intimidating, anyway.

Sans leans his skull against the line of bones in front of him, the faint hum of his magic slightly soothing his headache.

“The things I do for you, boss.”

Thankfully, his next trick requires no magic. He doesn’t know how he’s able to teleport; as far back as he can recall, he’s been able to do it. When Papyrus first learned about it, he wanted to use it to strike down their enemies, and as an intimidation tactic. Who wouldn’t be afraid of someone who could kill you at any moment, no matter where you tried to hide? But after a very long argument, he managed to talk Papyrus down. It was smarter to keep teleportation as an ace in the hole, for emergencies only.

This is an emergency. Sans opens a rift, and is only halfway through when the acrid stench of Hotland, a mix of sulfur and smoke, assaults his senses. Grimacing, he walks through. He’s right before the Lab. Steeling himself, he walks forward. The doors slide open before he can knock.

When he enters, he spots Alphys at her desk, claws typing away at her computer. The lights of the room are dimmed, but the wall of television screens keeps it rather bright. The televisions seem to be connected to camera feeds all around the underground. Including Snowdin. Fuck.

The Royal Scientist doesn’t look up as he steps closer, but continues to tap away on her computer.

“Really, Alph? Spying? You fuckin’ perv.”

“Ah, one of the skeleton brothers.” She adjusts her spiraled glasses. “ _Only_ one. How…curious.”

He stuffs his hands into his jacket pockets. “Cut the shit. You know why I’m here.”

At last she stops typing, wheeling around in her chair to look at him.

“Oh, do I.” She reaches behind her, pressing a key. The live feed cuts off from the screens, replaced with two angles of the fight with his brother, his failure magnified and multiplied. The cameras swivel to follow Sans as he hauls Papyrus away.

Sans seethes. Alphys had to have been actively watching them, for the cameras to track like that.

“Undyne is stopping by this afternoon.” She taps one scaly claw to her chin. “Imagine how she’ll react when I tell her you’ve mortally wounded her best soldier.”

With no magic left at his disposal, Sans has no choice but to seize her by the lapels of her lab coat.

“You shut the fuck up,” He hisses. “You saw nothing.”

One of her eyebrows arches up. “Is this any way to treat someone you need a favor from?”

“I’ll tell the king about those fucking abominations you keep in the basement.” He threatens. “I’ll tell their families. They’ll rip out your spine through your goddamn _throat_.”

Her face drains to a sallow yellow. She shoves him off of her.

“Alright, alright. I get it. Let me just grab a few things.”

As she paws around her cluttered workspace, Sans leans back against the wall. He tries to look cool and collected, like he isn’t leaning against the wall because he needs it for support.

Sans’ eyes unwittingly slip closed thanks to his exhaustion. He senses the static crackle of lightning magic, and dodges just in time to avoid an attack by Alphys, his eyes flinging open again. He glances at the wall he was leaning against just a split second ago; the wall is singed and smoking. Alphys doesn’t have a large reserve of magic like most leading monsters, so for this much energy to be put into an attack, she must really want to kill him.

“Can’t take my eyes off of you for a second, huh?” He jokes, broadcasting levity he doesn’t feel. “And we used to be such good pals.”

“I simply wanted to make sure you were prepared,” She explains, gathering needles and vials, and shoving them into a medical bag. “I’ll get the regeneration process going, but it’ll take a few days before he’s back on his feet again.” She zips the bag closed, slinging it over her shoulder. “So you’ll have to watch out for him until he recovers.”

The implication stings. “Don’t doubt my capabilities.”

Seeing that she’s ready to go, Sans grabs her hand, and yanks her back through his portal.

Alphys blinks rapidly, disoriented.

“How did you—?”

“Not important.” He interrupts. Sans hadn’t wanted to tip his hand entirely, especially not to Alphys. But the ferry would have taken too long. She glances at him, frustrated. He smirks. Perhaps it’s a good thing Alphys knows. She’ll scratch her brain and chase her tail for years trying to replicate it.

With a wave of his hand, the bones around Papyrus vanish, allowing Alphys to approach him. She tugs back the blanket, and doesn’t even flinch at the sight of the damaged area.

Sans doesn’t so much as blink as Alphys calls up his brother’s soul, its normal blazing white dull and flickering.

She hesitates a second too long, and Sans blurts out: “You can fix him, right?”

Monsters who had fallen down have been healed before, but Papyrus is barely holding on.

The Royal Scientist withdraws a container of glowing red liquid, and a large needle.

“I need to use an unconventional method, but of course I can.” Her mouth is a set line, eyes hidden behind her glasses. No way for him to discern if she’s telling the truth or not.

She fills the plunger with the liquid. After flicking the needle a few times, she then injects it directly into Papyrus’ soul.

The reaction is instantaneous. Papyrus jerks and writhes, nearly dislodging the needle.

“Help me keep him steady!”

Sans races over, pinning Papyrus’ shoulders down. Papyrus bucks and writhes, shouting incoherently, his feet dragging up and down over the couch cushions.

“Alphys, what the hell?”

“Just keep holding onto him!” She pushes the plunger the rest of the way down, injecting the remainder of the needle’s contents into Papyrus’ soul. He continues to struggle and cry out.

The red bleeds out from the injection point, until Papyrus’ soul is a deep red. Slowly, slowly, he falls quiet once more. Sans lets go of his brother once his limbs go slack again.

Alphys studies Papyrus’ soul critically. It glows a vibrant, bright red. Once more robust and thriving, but. Unnatural.

“What did you do to him?”

Alphys dismisses Papyrus’ soul.

“I gave him the determination to hold on.”

“You—You—” He grabs her again, shaking her hard enough her glasses are knocked askew. Her eyes are dark and dull. “You used that on my brother? After what it did to all those other monsters—”

“Shut _up_ , Sans.” Alphys brings a hand up, fixing her glasses. “Shut up and watch.”

For a moment more, nothing happens. Papyrus is unconscious, Sans is angry, and Alphys seems almost bored with the whole affair. But then, Papyrus’ whole chest starts to glow red, like a furnace heating up. Sans’ grip on Alphys slides away, and he goes over to crouch by his brother’s side. Dark red outlines of ribs and a sternum slowly form.

“What is this?”

“His bones are recreating themselves through his newfound determination.” Alphys gathers her things. “I injected far too much into the initial test subjects. This will be enough to heal him, nothing more.”

“…Thanks.” He grits out.

Alphys ignores him. “It should take about a week for him to heal entirely, and even then, he shouldn’t overexert himself for a while. I won’t tell Undyne about this, you can rest assured. But she will find out.”

Her voice is thick with derision. She doubts Sans can protect Papyrus that long. It makes his teeth grind together.

Alphys looks at him, as if waiting for something. He lets out a sharp laugh as he realizes.

“What the fuck do you think I am, your personal taxi? Get out of here.”

Face flushing, she stalks over to the door, jerks it open, and slams it shut behind her. He laughs. The fat bitch could use the exercise.

Sans returns to Papyrus’ side, looking him over. His features have smoothed out, no longer twisted in pain. Good, that’s good.

Cracking his knuckles so hard the joints ache, Sans sits and thinks on what the hell he’s supposed to do next. He should go back and erase the unusual, suspicious tracks he left while dragging Papyrus, but his soul twinges warningly. No magic until tomorrow, at the very least. And he can’t leave Papyrus here alone, unguarded. He can’t trust anyone to help him; even Grillby would abstain from intervening, despite their comradery and small friendship. The only one he can ever trust is—

“Papyrus.” He murmurs. That’s why he stays. Papyrus may push him past his limits, may scream and rant at him constantly, but. But. Sans can trust him.

And how has Sans repaid him? He shakes his head. What’s done is done, and there’s no way to change it. He needs to focus on what’s to come next if they’re to survive this.

Sans peeks out the front door. All is quiet and still, a light snowfall coming down. He carefully scuffs away the tracks leading to their door, to the house before theirs. If there’s any luck or God in this world, the snow will disguise the tracks thoroughly come morning.

He returns back inside. Papyrus is still fine, and a small ball of tension unspools in his chest. Now what?

Sans sinks to the floor, leaning up against the couch for support. He’ll have to keep up appearances. But Papyrus is so active, so visible. People will notice he’s gone. They’ll all be looking to him for some sort of explanation. He should mention that Captain Undyne took him away for special training. He should….He should…

Sans falls asleep.

~*~

When he awakens again, the morning has already come and gone, and the underground is well into the afternoon.

Sans rises, stretching. His body is still sore from the workout it’s been through the past few days, but he already feels worlds better than yesterday. He’s not constantly fighting with himself to not pass out. He checks his magic, and with some relief he finds that a sliver of it has returned. It’s better than nothing. Papyrus looks much the same as he did yesterday, red magic glowing as it repairs his shattered bones.

Sans shuffles over to the kitchen, roots around in the fridge. The pickings are few; Papyrus rarely eats much, so if Sans wants food he usually has to fetch it himself. All that’s inside the fridge now is a half-eaten burger from Grillby’s, and a dubious-looking jar of pickles wedged in the far back.

Sans pulls out the leftover burger and pops it in the microwave, watching the surface layer of grease on the meat sizzle and bubble. He’ll have to go to Grillby’s during the week, or people will start to wonder. Should he go more often, since Papyrus will be “off training with the captain”? But the more he’s around others, the more of a chance something might slip.

Sans hates this. He hates making important decisions. They were always up to Papyrus; he demanded the responsibility. It’s too heavy, too stressful. Sans just wants things to go back to the way they were.

The beeping of the microwave startles him, and he has to extinguish the magic that flares up in his eye socket.

Forgoing a plate, Sans brings the burger over to the living room. He flicks on the television, grateful for the the noise, the distraction. He eats, for once not caring too much about the crumbs he leaves scattered over the floor. There’s no mess he can make bigger than what he did to Papyrus.

He shudders. Sans is wary of summoning his blasters again, if they’re going to act independent of him like that. Sure, he was frightened, he was exhausted—but he did not give it the order to fire. It shouldn’t have happened.

Sans watches television all day, letting the mindless entertainment distract him.

As night falls, his body and magic crave more food. He has to leave. Sans sets up the barrier to guard Papyrus, then steps outside.

The walk to Grillby’s is too short for him to really collect himself. He pauses in front of the door, breath pluming out before him in the cold. He can do this.

Sans opens the door. Everyone swivels in their chairs to look at him. He swallows, feeling like what he’s done is written all over his face. He then realizes he’s lingering dumbly in the doorway, letting the cold air in.

Sans steps into the bar, letting the door close again behind him. He does his best to ignore the stares as he approaches the counter, and heaves himself up on a barstool. Grillby watches him silently.

“’Sup, Grillby?” He winces at the shakiness in his voice. The bar is silent.

“…No one has seen Papyrus today.” Grillby prompts him.

“Oh. I figured he would’ve shouted it through the streets.” He feigns surprise, soul pounding. “He left this morning for some special training with Captain Undyne.” He winks. “That means it’s just you and me for a little while. So how about some burgers to kick off this little vacation?”

His grin doesn’t waver, and after a moment, Grillby nods and disappears into his kitchen. Slowly, conversation in the bar picks up again around him. Sans takes a long pull from a nearby mustard bottle, but then restrains himself from chugging the whole thing down. He cannot afford to get drunk.

Grillby returns with his food. He begins to eat, a bit sloppier than usual; Sans wants to make his public appearance, and then get out. He soon notices that the fire monster hasn’t left to attend to his other customers, continuing to stare him down.

“What?” He grunts out. “I got something on my face?”

“…I am relieved. You have not shown up for the past several days. I was starting to wonder if you took a disliking to my cooking.”

Sans shrugs. “Blame the boss. You know how he gets in those little moods sometimes.”

The bartender seems content with his thin excuse, or at least unwilling to push the matter any further. Sans leaves soon after, not bothering to pay. Grillby knows by now to place it on his tab.

Once he gets home again, he rechecks on Papyrus. He seems to be improving. Rather than only a red outline of his bones, the bones have begun to fill in with the red magic. Sans’ hand cannot phase through the regenerating ribcage anymore; he’s met with a buzzing resistance. It’s working.

He can get through this.

~*~

The next day passed by in a relatively normal way. Papyrus is usually the one who keeps track of his sentry shifts, so without him, Sans hazards guesses as to when he’s supposed to be at his station. Not that guard duty truly matters all that much. Just like every other day before it, there was no sign of a human entering from the Ruins. On his way to and from his station, he keeps his guard up, and he doesn’t get killed.

But the day after that, he leaves his home in the morning to find all of Snowdin crowded in the center of town. He edges closer to see what all the fuss is about. Then he nearly smacks himself for his idiocy. They’re gathered around the bulletin board, looking at a long list. Today’s the day Captain Undyne is supposed to post her new rankings for members of the Royal Guard.

As monsters spot him, they shy away. Fearfully? Baffled, Sans approaches the posting. He reads it, and feels his soul drop through his proverbial stomach. Captain Undyne is ranked number one, of course. And right below her, at number two: Sans.

“What the _fuck_?” He scours the list—third, fourth, fifth—all the way down. Then reads it again. Papyrus’ name is nowhere to be found. Did she confuse one of them for the other? Sans knows it’s impossible, but it’s all his brain can come up with, smothered as it is by shock.

“This can’t be right.”

“Hey, hey, what happened to Papyrus?” A small bunny monster asks. “What did you do to him?”

“Nothing!” Sans snaps. “Papyrus is fine. I didn’t do anything.”

Another monster—His mother? Sister?—tugs him back so he’s out of Sans’ reaching distance.

“Of course you didn’t, boss.” She apologizes for the child.

The title strikes a nerve. “Don’t call me that.” He snarls.

Some monsters in the crowd scatter, others freeze in fear. He almost wants to laugh. A few days ago they would’ve tries to harass him, with Papyrus not present. And now they’re cringing in fear the second he raises his voice.

Confused and stressed, he stalks through the crowd and goes back home. If he truly is second-in-command, no one will dare pester him about going on his sentry shift.

As he shuts the door behind him, the full gravity of his situation hits his mind, and he sags back against the door for support. He can’t be Captain Undyne’s second-in-command. Hell, he can’t even be Papyrus’ second-in-command without screwing something up.

He cracks his knuckles. How does she know something happened to Papyrus? Does she think he killed him?

Sans starts pacing in the living room, thinking hard. As usual, his instincts scream at him to run. But. Papyrus can’t be moved yet. He’s effectively chained to this house.

The door suddenly slams open, with such force that it’s knocked off its hinges, clattering to the floor. Sans yelps in surprise, then moves to stand protectively in front of Papyrus.

Large boots stomp heavily overtop the fallen door, into the house.

Sans’ posture stiffens. “C-Captain.”

Captain Undyne lets out a low whistle as she peers around Sans to inspect Papyrus.

“You sure did a number on him, huh? He didn’t wake up at all when I came in.”

“How did you find out?”

She cackles. “You were careless, Sans. Just plain careless.”

Captain Undyne steps closer. Sans takes a nervous step back, legs bumping against the couch.

“When Dogaressa came to Waterfall to submit her monthly report, she asked how I could stand putting up with Papyrus for special training, or if I had just killed him out of annoyance and told you otherwise. Naturally I was confused. So I returned with Dogaressa, and we put that brilliant nose of hers to use tracking Papyrus’ scent. And you know what we found?” She grins wide, displaying her mismatched, jagged teeth. “Out in the woods, buried in the snow, was Papyrus’ armor. Or, rather, what _remained_ of it after you blasted it to bits. No wonder Papyrus keeps you around.”

She grabs his shoulders, crouching slightly to stare him in the eye.

“I always knew there was something about you, Sans. You can’t help but pay attention to Papyrus, but it’s really you everyone should be focusing on. So what was the fight about? He refused to treat you to Grillby’s, or something?”

“Captain, y-you should give Papyrus the position. I’m lazy, I’m a slob, I’m—”

“You’re a gem. A fucking diamond in the rough. It just took a little pressure to craft you into something great.”

“Please, I don’t want to—”

“You know what _else_ I always liked about you, Sans?” Her expression grows stormy, fins flaring out. “You always know when to shut up and do as you’re told.”

He gets the message. Sans clamps down on his next words. Anything he says here is liable to have her hurling spears at him. She nods approvingly.

“Good. As you know, you’ll have to move to Hotland.” She cranes her neck, inspecting the house. “You’ll probably have to settle for a smaller house, considering the crowding. I'm telling you now, I don’t abide slackers. I don’t care where you chose to live, but I expect you to make the move quickly.”

“But Papyrus—he still needs some time to heal.”

“I’ll solve that problem for you right now.”

Captain Undyne summons a spear, drawing her arm back to toss it.

“No!” Magic flaring up, Sans encases Papyrus in the cage of bones. The red light in his eye socket burns fiercely, casting a glow over Captain Undyne’s features.

At first she tenses, as if about to rush him. But then her posture relaxes, the energy spear dissipating in her fist. Sans, though perplexed, does not wave off his own magic just yet.

“Interesting. I always thought you hated the guy. But this’ll be so much better in the long run.” She waves her hand dismissively. “Sure! Take the time off. Let Papyrus recover.” She leans in close. “Have fun explaining to him that he’s out of the Royal Guard.”

“Why do you have to kick him out entirely? You know how badly he wants it. Can’t you just—demote him, or something?”

Captain Undyne sniffs dismissively. “He’s of no use to me anymore. You proved that to me.”

“He won’t just accept this. He’ll—He’ll fight you, captain, if you kick him out of the guard. He'll try to kill you.”

“Ah, but Sans. You see.” She claps Sans on the shoulder. “You’ll be the one to make sure that doesn’t happen.”

~*~

Four days later, life flickers back into Papyrus’ eyes. Sans is eating a small dinner in the kitchen when he hears Papyrus groaning from the living room.

He hurries over to his brother’s side. Papyrus is weakly trying to push himself into a sitting position, arms trembling. His ribcage is fully solid now, but still tinged slightly red.

“Easy, easy,” Sans helps his brother up, propping a pillow behind him to make sitting up easier.

“Sans.” Papyrus’ voice is unnaturally soft and feeble. “What—”

“It’s okay. Just—stay put here, okay? I’ll be right back.”

Papyrus blinks slowly up at him, disoriented.

Sans grabs a glass of water and returns to his brother. Papyrus is still too weak to hold the glass up himself, so Sans tips the glass between his teeth. Papyrus drinks greedily, messily. Sans wipes away the water that spills with the sleeve of his hoodie.

Once he sets the water aside, Papyrus is already starting to drop off again, listing to the side. Sans rearranges the pillow and blanket again so he can rest comfortably.

He reaches out, gently patting Papyrus’ skull. Then he realizes what he’s doing, and hastily snatches back his hand again.

A few hours later, Papyrus wakes up properly. He stands without Sans’ help, in his customary, ramrod-straight posture.

Sans approaches him cautiously, wringing his hands.

“Boss. I-I’m glad you’re awake.”

Papyrus growls, and hurls a few blue attacks at Sans. The shorter skeleton freezes, letting the attacks pass through him. Papyrus then turns his soul blue, dangling him in the air.

Even this little magic is too much, too soon. Papyrus is panting, sweat gathering on his forehead.

“You shouldn’t use magic yet. You still need to heal.”

“Don’t give _me_ orders.” He beckons with one finger, drawing Sans closer to him. “Now tell me what happened.”

Papyrus doesn’t remember? “I—I messed up, I really did, I’m sorry. But I fixed it, you’re going to be fine—”

“You attacked me,” Papyrus says. “What I want to know is _why_.”

“I didn’t mean to do it, I swear, I just lost control of the blaster. I’d never do that to you.”

Papyrus can’t sustain the attack any longer, and blue releases its hold over Sans’ soul. He crashes unceremoniously to the floor in a heap.

“Fuck,” He grumbles, picking himself back up again, rubbing at his now-sore jaw.

“How long have I been unconscious?” Papyrus demands more information.

“About a week, maybe.”

“The captain will be livid I’ve left my duties unattended so long without explanation.” His hands curl into fists. “I’ll deal with you when I get back.”

He stomps towards the front door. Sans darts in front of him, raising his hands to block the way out.

“Wait. You can’t go outside yet.” Sans scrambles to find a believable excuse. “You—You need to build up your magic again. Why don’t you just sit down, I’ll make you something to eat, and—”

“You’re keeping something from me.” Papyrus says shrewdly.

“M-Me? Of course not, boss.” Sans ducks around Papyrus, heading for the kitchen, so his brother can’t read his face. “Now, what do you want to eat? I got fresh food. Just name it.”

“Sans.” The commanding tone in his voice stops him in his tracks.

“You can’t be mad at me for this. It isn’t my fault. I d-didn’t ask for it.”

Papyrus folds his arms, staring down at him.

“You’ve gotta believe me. I tried to tell her I didn’t want it, I _tried_ —”

“Sans.” He says again, his patience for Sans’ apologetic ramblings at its end. “What is it?”

Sans sucks in a deep breath, then blurts out the whole ugly truth in a rush. “The captain found out about what happened. I—I’m Captain Undyne’s new second-in-command.”

Papyrus’ jaw drops open in shock. Shock morphs quickly into fury, and he grabs Sans, shaking him roughly.

“You’re lying.” When Sans says nothing, he repeats himself, rawer. “You’re _lying_.”

Again, Sans says nothing. Nothing he could say would make this situation better.

Papyrus throws him to the floor—two times in one day, how fun—and before Sans can pick himself up, Papyrus kicks him in the chest. He tries to curl up, protecting his ribs, but Papyrus rolls him on his back, pressing his weight down hard on Sans’ sternum. The irony of this does not escape him.

“F-Fuck you, Papyrus.” He spits out. “I could’ve dusted you, but I saved your life.”

“Am I supposed to be grateful?” He presses down harder, Sans’ bones starting to creak. He pitches his voice higher, mocking him. “Oh, thank you, Sans. Thank you so much for almost killing me and then changing your mind at the last minute. You’re so wonderful.”

Any more of this and his bones are going to splinter.

“I didn’t want this to happen.”

“Well, it did.” Papyrus unexpectedly get off of him, the massive pressure on his chest now only a dull throb. “It did.”

Sans staggers upright, rubbing at his chest. Papyrus isn’t looking at him anymore. Isn’t glaring. Isn’t doing anything, just staring down at the floor.

“Papyrus…?”

“Get out of here.” His voice is flat. The anger has drained away, replaced by weariness.

“No, please. I can still fix this.”

“Leave.” Sans flinches. “I never want to see you again.”

Sans grabs Papyrus’ arm.

“Please. Hurt me all you want. Punish me. But don’t…don’t send me away.”

Papyrus shoves his arm off.

“I don’t want you here. This—This alliance between us is finished. Get. Out.”

Sans backs away slowly, waiting for Papyrus to change his mind. No such change is forthcoming.

Whimpering slightly, Sans throws open the door and starts running. Snowdin’s residents shy away from him. Unimpeded, he runs into the woods. He just keeps running. He doesn’t know where he’ll go. He could move to Hotland, could step into the role of second-in-command, but. He can never do that. There’s no point now, no point to anything. Papyrus is finished with him. Doesn’t want him anymore.

Sans finally slows to a stop, doubling over, gasping for air. He sinks to his hands and knees, pounding his fist into the ground in frustration and anguish.

“Damn it! Damn it, damn it!” Wetness trickles down his face, plopping into the snow below.

Sans touches his cheek, fingers coming away wet with tears.

“And now I’m crying? God, could I be any more pathetic…”

He stands, scrubbing furiously at his face to remove the evidence of his crying.

“Um, hello?”

Sans whirls around. A yellow flower is smiling up at him, bobbing nervously on its stem.

“Howdy. My name is Flowey.”


	3. Petals

After the flower introduces itself, Sans just stares. Its smile dips.

“And you’re Sans, right? Sans the Skeleton.”

“Beat it,” He snarls, about ten seconds away from blasting the offending monster to plant matter.

“Just hear me out.” The flower’s voice is high and earnest. Like a little boy. “I want to help you.”

“You know how you can help? _Leave me alone_.”

“I can fix this for you! All of it!” Flowey insists.

Hysterical laughter bursts free from Sans. “There’s nothing left to fix. It’s all ruined, and it’s all my fault.”

“Please, let me help you. It’s not too late.”

“Oh yeah? And what can you do?”

“What if…” Flowey begins, hesitantly. “What if I told you I have the power to manipulate time? We can go back to before you ever hurt your brother!”

“Oh, _fuck_ off.” Stuffing his hands in his pockets, Sans starts walking away.

“Wait!”

Sans feels the earth shift behind him, and something lashes out whip-like, curling between the bones of his shin, tugging him back hard enough that he falls to the ground. He coughs out a mouthful of snow, and rolls over. A green vine is wrapped around his leg, connected on the other end to the flower, who’s looking more skittish by the second.

“Oh, dear, I didn’t mean to pull that hard. Are you alright?”

Sans calls forth a Gaster Blaster. In a fraction of a second its maw cracks open wide, unleashing its beam of magic.

Then the whole world seems to stutter.

Sans blinks, and his blaster is gone, like it was never there. He calls forth the four of them in his soul, and they all respond. Unhurt, undamaged.

“Now Sans. Let’s please just talk about this—”

He summons all of them this time, and they blast the flower from every direction.

But then they’re all tucked back in the reserve of his magic, as if they’d never been fired.

“I don’t want to fight you, Sans.” Flowey is firm. “I don’t want to fight anyone.”

Sans’ mind is reeling. What the _fuck_ is going on? He doesn’t believe the flower can actually manipulate time, as it says. That’s impossible. So what _is_ it doing? Is there a magic that exists that can manipulate the mind?

He tries to tug his leg away, but the vine tightens its grip accordingly.

“Let go of me.” Sans’ voice is taut with fear.

“If I do that you’ll just run away. Why won’t you let me help you?”

“I don’t want your help. Just—Just leave me alone!”

They stare at each other for a moment. Finally, the flower sighs, its yellow petals drooping.

“Fine.”

Flowey retracts its vine. Not giving the monster a chance to even speak, Sans takes off running, kicking up snow in his wake. He hazards a glance back. The flower hasn’t moved to follow him. Good.

Sans runs until his body threatens to collapse on him if he doesn’t stop to catch his breath. He sits down, leaning against the trunk of a tree. The bark is rough and uncomfortable, his jacket not providing enough cushioning.

Random trivia pops into his mind, the way it does when one detaches themselves from reality. In the early years, monsters had fretted over overcrowding. Some had pictured an underground filled with houses, the forest cleared away, the marshes drained, the magma built over with asphalt. Just rows and rows of monsters pressed together in miserable existence. Of course, that particular fear didn’t last long.

In spite of himself, his mind returns to Flowey the Flower. Monsters have approached Sans before with false kindness, so sickly sweet and disgusting.

But the flower…it seemed genuine. Sincere. Sans rests his chin on his palm, thinking. He’s never met someone like Flowey before. Sympathy and affection are weaknesses stamped out of monsters while they’re still children. And the flower—it sounded like a child, but Sans’ gut tells him its voice is deceptive.

“What the hell is going on?” He mutters.

He knows he won’t get any answers just sitting here, staring at the darkening sky. So he stands, brushing snow from the back of his shorts.

Sans steps through one of his shortcuts, back to Snowdin. He pushes open the door to the inn. The bunny monster’s ears flatten to the back of her head at his approach. She nervously pushes a golden key across the counter to him. Probably the best suite in the hotel. He snatches it up, and trudges upstairs to the rooms. Because fuck if he’s sleeping out on the cold hard ground. Papyrus won’t look for him here. Won’t look for him at all.

Don’t think about it. Sans repeats the phrase like a mantra in his head. Don’t think about it. Shove it all into a box and turn away from the box.

Sans enters the room that matches his prediction. The bed is excessively large, replete with plump pillows. The bedframe and furniture are ornate, the wood a dark, rich color. Sans runs his finger bones over the patterns carved into the wood; the Delta Rune, the king’s crest. This stuff puts their lumpy little couch to shame. Papyrus never bothered to invest much in furniture; being so active, it’s not a priority to need a comfortable place to sit.

The sound of his neighbors’ snores bleeds through the thin walls. Sans goes over to the wall, beating on it to wake the monster up.

“Shut up.” He barks.

They must take his command to heart, because he hears a bit of shuffling, and then nothing more.

Sans flops onto the bed, his stubby frame barely filling a forth of it.

He was ready to give up on everything, to just lay around in the woods until he crumbled from starvation. But that damned flower has piqued his curiosity. He needs to know more.

~*~

Sans’ thoughts keep him from grabbing more than a few hours of sleep. The bunny is straight at attention by the time he reaches the bottom of the stairs; she must’ve been alerted by his plodding steps.

She meshes her hands together, lips twitching upwards in a forced smile.

“Have a good rest, sir?”

Sans grunts, not bothering to properly respond.

The innkeeper is relieved, bowing slightly as he leaves.

Sans looks to the left. From this far away, he can just barely see his house. Is Papyrus doing alright? He needs more time to recover, but knowing him…

Sans is halfway back to the house when he realizes what he’s doing. Stupid. He shattered Papyrus’ ambitions. He has no right to be there anymore.

So Sans turns around, heading back to the forest before the sealed ruins of Home. He tromps through the snow and fallen branches until he reaches an isolated area.

Sans stuffs his hands in his pockets, feeling foolish.

“Um. Flowey? You there?”

He waits, fidgeting. Three minutes pass.

“Flowey? I want to talk.”

More time passes. This was a dumb idea.

Sans is about to leave when the flower pops out of the soil in front of him.

“Howdy, Sans!” The flower is beaming. “Thanks for giving me another chance!”

“Sure. Whatever.”

“I just really wanted to help yesterday. I didn’t mean to scare you.”

Sans bristles. “I wasn’t scared. You were just getting on my nerves.”

“And it’s my fault,” Flowey is gracious. “I won’t try to keep you against your will again. I promise.”

“Heh. Promises don’t hold much water around here, kiddo.”

“Well, then I’ll prove it to you.” Flowey insists. “I won’t do anything you don’t want to. You’ll see.”

“…Why are you doing this for me? I don’t know you. Even if I believed you could manipulate time—which I don’t,” He tacks on hastily, when Flowey’s expression brightens further. “It makes no sense for you to use it to help me out.”

“Who hasn’t heard of the Skeleton Brothers?” Flowey explains, with a bit of nervous laughter. “You’re the talk of the underground! It’s impossible not to hear at least a little something about you.”

Sans glares. “If you aren’t gonna level with me, I’m done here.”

“Alright, alright! I…” Flowey gathers itself. “I did hear about you through the town. That’s not a lie. But there’s more to it than that. You care about Papyrus a lot, don’t you?”

Sans can’t answer. Can’t confirm the weakness, but can’t deny it either.

“I had a sibling too, very long ago. Back when I still had my old body.”

“Old body?” Sans parrots, incredulous. “You mean to tell me Vegetoid isn’t your distant cousin?”

“I died, very long ago.” Flowey’s flat statement punches through Sans’ poor attempt at humor. “But someone brought me back. I was filled with this determination to not give up.”

Dots begin to connect in Sans’ mind. After Sans and Papyrus left New Home for Snowdin, Sans lost contact with most everyone at the Lab, save Alphys. She’d message him from time to time to request his scientific input. Sans couldn’t very well deny her; if the king learned he refused to collaborate with the Royal Scientist, Sans would’ve been dusted.

At first they had been small things, minor equations she needed another eye to look over. But one night she actually called him. He knew something was wrong from that alone; Alphys despises the nasally tone of her own voice. Her experiments with what she called “determination” had gotten out of hand. Sans helped corral the melting, mutated things into the basement level of the lab. But neither he nor Alphys ever found her initial experiment, a golden flower from King Asgore’s gardens.

“Asriel.” He realizes.

“ _Flowey_.” The boy corrects him, the angriest Sans has seen him yet. “That name doesn’t belong to me any longer.” Then, lighter: “I’m a new monster. I’m Flowey the Flower. But, if you know who I used to be, you understand why I want to help. I know what it’s like to care for a sibling. To love them. And to lose them.”

The fallen human. Sans had never met them, but everyone knew the prince and the first child had become thick as thieves after their initial meeting.

If this flower is truly a being of determination, time travel is actually feasible.

“But you have the option I never had. You can go back. You can redo.”

“So why haven’t you done it already?”

“Because in order for it to mean anything, you’d have to remember this timeline. So you wouldn’t make the same mistakes.”

“And I wouldn’t remember? Hell, we wouldn’t all remember?”

Flowey bobs low on his stem. “I’ve reset the timeline before.”

“ _What_?”

“You don’t remember.” Flowey says, sadly. “None of you ever do.”

Nervous laughter erupts from Sans. “Cute joke, kid.”

“Once I discovered I had this power, I’ve tried to use it to help people. Mostly little things; keeping a monster from having a bad fall and breaking their arm, for instance.”

“Knock it off with the saintly act. Monsters die every day. Hell, just this week I saw two guards in the canine unit die. Where were you then?”

“My powers are not unlimited. I tried to help everyone at first, prevent everything bad from happening, but I soon realized I couldn’t. It was too much to keep track of from reset to reset. And monsters…so many of them want to hurt each other. I don’t understand it.”

Sans shrugs. “That’s the way it’s always been. Eat or be eaten. Kill or be killed.”

“I don’t agree with that.” Flowey says softly. “But if I force my way into others’ conflicts, make them stop fighting only because I will it, then I’m no better than them. So instead, I started to help people with accidents. When terrible things happen that they never wanted to happen.”

“So do any other monsters know about these resets?”

Flowey shakes his head. “Everyone else I’ve always managed to help somehow without getting them involved. But the situation with you and Papyrus is more complicated than I thought it would be.”

“Oh?”

“Sans. This isn’t the first time we’ve had this conversation.”

Chills crawl up Sans’ spine. “The fuck did you just say?”

“I’ve tried to convince you before. That failed, and I reset on my own. Nothing worked. It was like something was fighting back against me, pushing things back towards their inevitable outcome. It has to be you that goes back, I’m sure of it.”

Sans waits for a feeling of déjà vu to wash over him, but nothing hits him. Not one shred of this conversation rings familiar in his mind. How. How could this have happened already, and he not realize? His rational mind struggles to make sense of the irrationality.

“Sans?” He must’ve zoned out; the flower is peering up at him with concern.

“I’m fine.” Sans drags a hand over his face. “Just keep going.”

“I’m pretty sure that you have to be the one to fix this problem between you and your brother, but to do that you need to be able to remember when you go back.”

“So how are you going to manage that?”

“It’s a complicated thing—”

“Try me.”

“That’s not important right now. What you need to know is I can make it so you remember.” Flowey hesitates.

“I’m sensing a “but” here.”

“But…you won’t be able to forget again. I can’t take off your blinders and put them back on again—they’ll just be broken.”

“So if you were to go back in the timeline again—which, let’s face it, you will—I’ll remember everything? And I’ll have to live the same days over and over again?”

“You wouldn’t remember everything,” Flowey clarifies. “Just the important things. The big things.”

Even the flower can’t make an endless, frustrating loop sound sweet.

“No. Not happening.”

“At least think it over.” Flowey implores. “You don’t have to make your decision right now.”

~*~

Sans shifts his weight as he stands in front of his door. He’s stood here long enough for his legs to get tired. He’s sure the other monsters are surreptitiously eyeing him in confusion.

He can see through the window that the television is off, the living room dark; Papyrus must be in his room. If he’d been downstairs and spotted him, he would’ve thrown Sans off the front stoop in a heartbeat.

Sans grasps the doorknob, but can’t will himself to turn it. He has to fix this problem with his brother one way or another. He can’t rely on Flowey’s method, not with all the strings attached. So he’ll have to handle this his own way.

Finally, _finally_ , he enters the house, climbs the stairs. The lights aren’t on beneath his brother’s door. Could he really be sleeping, at such an early hour? Then again, Papyrus is in a rather bad way.

Sans knocks twice, knuckles rapping on the wood. There’s no response, and Sans is hardly surprised. He almost doesn’t want to be heard.

He opens the door, wincing as it creaks. He squints in the darkness, unable to see more than the faint outline of the bed from this distance.

“Boss?” He says, softly. Sans eases the door open wide, the light from the hallway illuminating Papyrus’ room. The bed is empty, covers still made up.

Dread roils in his gut. Sans combs the entire house, even his own room—Papyrus is nowhere to be found. He checks the shed by their house, which his brother uses to store his weapons and such. He’s not there. Sans even checks the small lab he set up behind their house. Nothing is inside but scattered blueprints for failed machines, and crusty photo albums.

Sans teleports to Papyrus’ sentry station. The counter is covered with a light dusting of snow, which Papyrus surely would have cleared off if he’d been working. He punches in Papyrus’ cell number with trembling fingers, but it goes right to voicemail.

He teleports to Grillby’s next, even though it’s right next door. He slams the door open. Grillby is at the bar, as usual. A few of the regulars are scattered about, as well as the Dogi.

“Where’s Papyrus?” He asks, hardly disguising his fear.

Dogaressa lets out a chuffing laugh under her breath. Not in the mood to play games, he envelopes her soul in blue. She yelps as he yanks her from her seat to follow him out the door.

“How nice. A volunteer to help me look.”

Sans goes outside and throws her into the snow. Dogamy lingers in the doorway, growling at Sans, but too chickenshit scared to actively challenge him. Dogaressa struggles to stand, but Sans just presses down harder with his magic, shoving her nose to the ground.

“Find him.” Sans orders. “Or I’ll kill you both.”

Dogamy whimpers impotently, but Dogaressa is furious. She’d tear him apart if he released her soul. But since he won’t, she has little choice but to do as he demands and start sniffing out Papyrus.

Once she truly gets to work, he lets up on the pressure of blue slightly, just enough so she can slowly follow Papyrus’ scent. Dogamy trails behind them, making sure not to piss Sans off by hovering too close.

Dogaressa leads him back to his own house, but stops short on the front stoop.

“He left here,” She says between sniffs. “Several hours ago.”

She follows the trail to the edge of town.

“He must’ve gone into Waterfall.” Dogaressa concludes.

He probably went to the captain’s house. Oh God.

Dogaressa’s muzzle wrinkles, and she makes a disgusted noise.

“What is it?”

“Doesn’t smell like fresh bones anymore. Smells sour.”

This is just getting worse and worse. If Papyrus is still sick, and he went to challenge Captain Undyne…

Sans releases his hold on the dog monster and winks out of existence in Snowdin, popping into Waterfall, just outside Captain Undyne’s door.

He jerks it open, and has to dodge the spears immediately thrown at his head.

The barrage halts after a moment, Captain Undyne jumping off her fighting position on her dining room table.

“You can’t show up unannounced like that.” The captain chastises him.

“Have you seen Papyrus?” Sans moves through the house, searching for a trace of his brother. There’s nothing, not even a speck of dust to signify something terrible had happened here. Had he beaten his brother here? Had Papyrus gone somewhere else?

“You’ve lost track of him already?” Captain Undyne sneers.

“So you haven’t seen him? He hasn’t come by?”

“You better pray he never shows up here, or I’ll make a pincushion out of him”

Not here, never was here. Captain Undyne isn’t one for subtle treachery.

Sans runs from the house, back into the marshlands of Waterfall.

“Hey! Sans!” The captain calls after him, no doubt annoyed with his less-than-subservient manner of attitude. But she’s not riled up enough to pursue him, as no further spears are flung his way.

His boots make wet slopping sounds as the marsh gets deeper, some of the cold slime creeping into his boots and splashing up his legs.

“Papyrus?” He calls, and the luminescent echo flowers mimic his cry.

It’s growing darker, harder to see, his way lighted by only the faint glow of the flowers and his one burning red eye socket.

He stumbles over his own feet and trips. He starts to spit out water that’s chunky with algae when he freezes, hearing a voice in the flowers that isn’t his own.

“Pap—” He smothers his instinctive cry with his hand. Only a few of the flowers around him parrot him. Sans moves further, treading softly as he’s able, listening hard. Some of the flowers repeat snippets of meaningless conversations, but finally he locates the flower with his brother’s voice. He tugs on the petals, and the echo flower emits a garbled cry that sends chills down his spine. Papyrus is in pain.

Sans follows the flowers that copy the cry, and finally he’s led to his brother. Papyrus is curled on his side, half-submerged in the muck.

“Papyrus!”

Sans touches his brother’s shoulder, but Papyrus flinches away from him.

“Papyrus, it’s me, it’s Sans—” His words catch in his throat.

Papyrus twists his body to face him. His face is melting, the bone around his eye sockets dripping down his jaw. Sans can see the outline of his ribs through his shirt, misshapen, congealing together.

Papyrus reaches out a hand towards him, bones cracking and collapsing. Part of his finger splatters onto Sans’ hand. Disgusted and horrified, Sans jerks his hand away.

“ **Sanssssssss**.” Papyrus’ voice is plaintive and distorted.

“Oh fuck, oh fuck—just stay calm.”

His brother lurches towards him again, and Sans staggers back a few steps.

“ **Sssssssaaaaanssssssss**.” Papyrus burbles.

“I’ll get Alphys, she’ll know what to do, she’ll—” She’ll put him in the basement, like all the others. She miscalculated. She can’t fix this. She’s ruined his brother like all the rest of them. Unable to die, unable to live. His breaths come in short gasps. He can’t look at this anymore.

Sans staggers away, ignoring the faint cries of his brother.

Part of his brother is still on his hand. Sans kneels in the shallow water. He takes the cuff of his right sleeve and starts scrubbing at his left hand. The off-white stain of bone is worn away, but he keeps scrubbing, Papyrus’ moans of pain echoing all around him.

“Sans, stop it. You’re going to hurt yourself!”

Flowey has appeared. Sans grabs the monster by the stem so he can’t escape.

“Do it. Take me back.” He says, savagely.

“S-Sans,” Flowey sounds like he’s choking. Sans is nearly crushing him in his grip. “You’re upset. This isn’t the best time to be making this decision.”

“Send me _back_. Send me back, send me back.” Sans begs. “I’ll take anything over this, just. Do it.”

“…Fine.” Flowey closes his eyes for a minute, then opens them again.

“It is done.”

“What—”

The world empties. A black expanse. Sans is crouched, clutching empty air in his hands. His clothes are dry. And Papyrus’ cries are gone.

Everything reappears in a rush of light and sound and sensation. The frosted pine scent of Snowdin floods his senses. Greater Dog is running towards him, teeth bared, muzzle red—

A wall of bones crackles into being before him. Not his magic. Sans whirls around.

“Papyrus.” He gasps in relief.

His brother is there, healthy, armor shining with a fresh polish.

Without thinking about it, Sans hugs him fiercely around the torso.

Papyrus shoves him off.

“What are you _doing_?” His brother asks, repulsed. Greater Dog takes this opportunity to scamper away. Papyrus lets him leave.

Tears, unbidden, spring to Sans’ eye sockets.

“You’re okay!” Sans cries. “I can’t believe it, it worked…”

Papyrus crouches down so he’s at the shorter skeleton’s eye level. He looks him over critically, discomfited.

“What the hell is wrong with you?”

Sans reaches out, patting his brother’s skull with his hands. Firm, solid bone. Papyrus is okay. He’s _okay_.

“Stop that.” He grabs Sans’ wrists, tugging his arms away from his face. His grip is strong.

“Sorry, I’m sorry. Just give me—” He takes a few shuddering breaths, trying to calm himself down. “I just need a moment.”

“You need to go home.”

“W-What?”

Papyrus takes him by the arm, and starts tugging him towards Snowdin. Sans lets himself be led.

Monsters stare as they pass, at Sans being led around like a child. But none dare say a word in jest, still too terrified of Papyrus.

Once at home, Papyrus pushes him onto the couch and unceremoniously throws a blanket overtop him. This is the most affection Papyrus has shown him in years.

“B-Boss, I’m alright now.”

Papyrus crosses his arms, huffing. “You clearly aren’t. I can’t believe you’re too weak to handle something as simple as sentry duty without breaking down.” Even though the words are cutting, their edge is softened by his tone.

As Papyrus goes to leave, Sans moves to follow. Exasperated, Papyrus pushes him back onto the couch.

“Stay here for the remainder of the day. I have to cover the rest of your shift if I still want to impress the captain.”

“But I can still—”

“No, Sans. You’re not in your right mind to do anything. You’re asking to be dusted. Imagine how that would make me look! Stay here so you don’t embarrass me further.”

Papyrus marches out of the house. Sans sinks back into the couch. He pats down his jacket until he locates his phone, and checks the date. Just as he thought, he’s jumped back in time to the day Captain Undyne posted the missive for the re-ranking. Sans grimaces. He’s not looking forward to reliving the grueling days of training again. Although…he might not have to go through it again. The course of events has already been altered—instead of firing Gaster Blasters until he pukes, he’s cozying up on the couch. And he hasn’t even been here a full day yet.

Sans wants to seek out Flowey, to discuss the differences, but sleep beckons him.

Sans goes to sleep—and sleeps in. He had nightmares, but thankfully, his recollection is muddled—he doesn’t want to revisit the horrific image of Papyrus melting.

As he pushes the blanket off and stretches, he notices light is shining in from the windows. Odd. Papyrus never lets him sleep this late.

He checks Papyrus’ room; it’s empty. Trying not to fly into a panic, he dials his brother’s phone number. Nothing happens on the first day. Papyrus doesn’t even visit Captain Undyne. So why does he still feel so uneasy?

The phone cuts to voicemail just as the front of the house _explodes_. Sans’ phone is thrown from his hands, and he nearly losses his footing, buffeted by the force of the explosion.

 He scrambles to the railing, dodging falling plaster. In the rubble of his house stand the canine unit—minus Doggo, of course. But led by Greater Dog, all geared up for a fight.

“What are you _doing_?” Sans shouts. He hears a crack from beneath him, and clumsily jumps down to the living room before the floor he was standing on collapses. Sans coughs as he inhales plaster and wood dust kicked up by the wreckage.

With howls and snarls the canine unit dart towards him. Sans frantically dodges swinging axes from the Dogi, as well as magical spear attacks from Greater Dog. Sans summons forth his Gaster Blasters, assigning them each an individual to pursue. Lesser Dog gets underfoot and lunges, biting down hard onto Sans’ arm.

“Fucker,” Sans swears.

Something is wrapped around the monster’s long neck.

 Papyrus’ scarf. Like a trophy from a kill.

“No.” He breathes, feeling like all the air has been pushed out of his body. “No!”

The Gaster Blasters fire. They all miss, but they serve as enough of a distraction. Sans grabs Lesser Dog’s soul with his blue magic, and starts knocking him against the still-standing walls of his house. He’s forced to release the monster as Greater Dog’s spear plunges towards him, shattering his concentration. Lesser Dog springs upright, muzzle broken and bleeding, but his eyes still full of fight.

This is a coup. The canine unit lost command over the town once he and Papyrus moved in. They were constantly looking for opportunities to seize control once more, and at last they found one. If Sans hadn’t fucked up and freaked out over his brother yesterday, he and Papyrus would’ve been together for most of the day, as usual. But Sans left Papyrus alone. They seized the rare opportunity, must’ve taken Papyrus by surprise—

He raises up a field of bones from the floor. The Dogi and Lesser Dog, nimble, spring upwards. Greater Dog is weighed down by his armor, and the bombardment of magical attacks rips him to shreds.

Sans doesn’t let up for a second, firing off the Gaster Blasters again and again to keep his remaining enemies constantly moving and unable to retaliate.

Lesser Dog is going directly for him again. Sans throws out a horizontal bone at knee-level. It only knocks off 1 HP, but it sends Lesser Dog sprawling forward on his face before Sans.

Sans presses his boot down on Lesser Dog’s head, relishing in the sound of bone splitting and brain matter squelching.

Sans bends down over the dusty pile, snatching back Papyrus’ scarf, winding it tight around his left hand and arm.

The only remaining members of the canine unit seem to realize they’ve made a terrible mistake in challenging him. They try to run away.

“Where do you think you’re going?”

Sans grabs Dogamy by his soul, lifting him high in the air. His feet kick uselessly in midair as he yelps in panic. Dogaressa whines for her husband, dancing back and forth on her feet right below him. She then scampers over to Sans, groveling and scraping.

“We’re sorry, so sorry.” She snivels. “We’ll never challenge you again. Anything you want, you’ll get it. Just spare my Dogamy.”

“You know what I want?” Dogaressa’s ears lift a little, daring to hope. Sans’ eyes go pitch black.

“I want my brother back.”

Sans releases his hold on Dogamy, and the monster plummets back to the ground. Dogaressa keens loudly at the smear of fur and blood that was once her husband. Sans drives a bone through her throat, watching as it drains her HP to nothing.

At last, Sans is alone, surrounded by piles of dust and his ruined home. He sinks to his knees, his Gaster Blasters and other bone attacks dissolving away. Papyrus’ scarf is still wound around his fist. He has to go back again. This is no better than before.

Flowey appears beside him, looking sad and small. He extends a vine towards him as if to provide comfort. Sans smacks it away.

“I’m sorry—”

“Why didn’t you warn me that Papyrus would be attacked?” Then, another thought: “And why didn’t you stop this from happening?”

“I tried to save him. They ganged up on him all at once, as he was inspecting one of his human traps. I tried to grab them, but something would always go wrong. No matter what, Papyrus ended up…” Flowey swallows, gaze flashing to the red scarf then back up to Sans’ eye sockets. “We need to try it again.”

“What’s the point? Why even try? Everything’s just going to get worse and worse, no matter what I do.”

“Don’t speak like that.”

“And why not?” He snarls. “Papyrus will just keep getting hurt, and I won’t ever forget. I can barely handle what I’ve seen already. I don’t want to see any more.”

“There has to be a way to keep Papyrus safe. I’m sure of it.” Flowey insists, valiantly trying to be a spot of optimism.

An idea, born of rage and guilt and grief, flickers to life in his mind. His grin widens, and Flowey edges away from him a little.

“I’ll kill them. I’ll kill them all. Captain Undyne. Alphys. The dogs. All of them. Everyone. No one will ever hurt Papyrus again, because I won’t let them.”

He goes to grab Flowey by the stem again, but he has grown wary since Waterfall, and twists out of Sans’ reach. Sans springs up; but when he takes three steps forward, Flowey backs up by five.

“Take us back, Flowey.”

“No. No violence.” He’s adamant. “It’s that attitude that started this whole mess. Violence just results in more violence!”

“Violence is all monsters understand! You can’t change who we are.”

“Sans, I want to help you.”

“Then take us back.”

“Can’t you see that this would only make you miserable? You’re a good person, Sans. Such violence would drive you mad.”

“I don’t _care_ what it would do to me!” He clutches his skull. If he had hair, he’d be tearing it out. “I don’t care. I just want Papyrus to be alright. I’ll do anything.”

“I won’t help you commit a genocide of monsterkind.” Flowey’s voice shakes. “Figure out a new plan. Until you can come up with a solution, I won’t reset for you.”

“Flowey—!”

Sans reaches out to snatch up the flower, but his hand only closes around empty air.

Flowey is gone.

 


	4. Past

**Notes for the Chapter:**

> Hey folks. This chapter's a bit strange, so just bear with me here. A lot of lingering questions should be answered in the following chapter.
> 
> Also, give heaps of love to Jovialknave over on tumblr, who has made this amazing art of the first chapter: jovialknave.tumblr.com/post/139967939152/sans-soaks-up-the-rare-praise-soul-pulsing-with-a

In their shared bedroom, Sans is doodling absentmindedly in a notebook when he hears Papyrus huff in displeasure. He looks up from the half-finished sketch of a dog to see Papyrus hunched over, glaring down at the newspaper laid out in front of him on the table as if it had personally offended him. Sans had picked through the paper earlier to read the funnies—but his brother only ever has eyes for the puzzle section.

Sans sets down his pen and scoots over to his brother’s side.

“What you got there, bro?”

Papyrus pushes the newspaper over to him. He rubs at his eye sockets tiredly.

“It just doesn’t make sense! I’ve run it through my head a thousand times and I can’t figure it out.”

Sans looks at the junior jumble, several failed attempts scribbled into the margins of the page. The word unscrambles in his mind in a few seconds.

 “Waffle,” He declares.

“What?” Papyrus snatches back the paper, squinting as he brings it close to his face. “You’re lying.”

“…Why would I?”

Papyrus taps to two of the letters—the “f’s”.

“These are clearly “t’s”, brother.”

Sans stares blankly at him.

“What?”

“Hold on, bro.” Sans grabs a picture book off their bookshelf, and flips it open to a random page. He points at the large text. “What’s this say? Can you read it?”

Papyrus puffs up. “Of course I can! “And then Fluffy Bunny went to the park.”.”

“And this?” He points to a random word on the newspaper. Papyrus peers at it closely.

“T…T…something.”

Sans puts a hand on his brother’s arm.

“Pap, I think your eyesight has gotten a little funny.”

Papyrus frowns.

“Funny how?”

“I think we should ask Dad to get you some reading glasses.”

“No!” Papyrus blurts, discomfited.

“But—”

“Promise me, Sans.” Papyrus pleads. “Don’t tell him. It’s—It’s just smaller words, right? It won’t be a problem.”

“But how are you going to read? How are you going to do your puzzles?”

Papyrus loops an arm around Sans’ shoulders, tugging him closer.

“Silly bones! That’s what I have you for. I hereby designate you as my personal book reader!”

“That so?”

Papyrus nods in a kingly way.

“Say, Pap. What building has more stories than any other?”

“Er…King Asgore’s castle, I suppose.”

“Nope—a library.”

Sans watches with glee as his brother works through the pun, face morphing from contemplative to irritated. Papyrus lightly cuffs him on the skull.

“That’s enough of that!”

The faint sound of the front door opening downstairs draws their attention. Papyrus bolts from the room, gleefully shouting:

“Father! Father!”

“Hello, Papyrus.”

Sans follows behind, at a more sedate pace. Papyrus hardly lets their dad get in the door before he hugs him around the waist. Sans takes the grocery bags from his father’s arms so he can reciprocate the hug for a moment, then gently pry Papyrus off of him.

Gaster walks over to the kitchen, and meticulously puts the groceries away in the same order as he always does. Papyrus rocks back and forth on his heels in excitement, and even Sans can’t deny there’s a flutter of happy anticipation in his ribcage.

When Gaster sets the last can on the shelf, he turns to find two expectant gazes. He chuckles lowly.

“My my. What’s all the excitement in the air for?”

Papyrus doesn’t play along with his feigning ignorance act.

 “ _Father_.”

Gaster grins. “Grab your jackets and rain boots.”

“You mean—?” Sans jumps in before even Papyrus can say anything, eyes bright.

“Yes.  We’re going to Waterfall.”

Papyrus gives a short yip of joy, darting back upstairs.

“Thirteen years old.” Gaster muses. “That’s quite a milestone.”

Sans fidgets, suddenly a bit embarrassed. “It’s not a big deal.”

“You two are really growing up.”

“I’d say Paps is growing more than me.”

“I’m back!” Papyrus has returned with his and Sans’ rain boots in record time. After swapping their shoes and shrugging on their raincoats over their striped shirts, the brothers are ready to go.

New Home’s streets are choked with monsters heading home for the evening rush. Gaster holds Sans and Papyrus’ hands so they don’t get separated in the large crowd. When they get to the River Person’s stop, they have to wait in line behind several commuters. Papyrus vibrates with glee and impatience, and Sans isn’t too far off from it himself. Though he and his brother both love Waterfall, their father is rarely home and able to take them, always wrapped up in his projects for the King.

Finally, it’s their turn to board the boat.

“Tra la la.” The River Person hums lowly to themselves as the boat glides down the river. Papyrus squats, peering curiously at the dark waters. When he leans too close for Sans’ comfort, he grabs the hood of his brother’s raincoat and tugs him back.

“Knock it off, Sans.” Papyrus swats away his hand.

“Just be careful, alright?”

Papyrus scrunches up his face at him; if he had a tongue, he’d be sticking it out at him right now.

“There is no one more careful!” Papyrus declares proudly, puffing up his chest a little. He sneaks a glance to see if Gaster is watching. He is, and with a small smile. Papyrus is emboldened. “Truly I am the greatest at being careful! The carefullest! No one is more full of care than I am!”

“Sure thing, bro.”

“Nyeh heh heh.”

It seems like it’s hardly been a minute, and they’re already pulling into Waterfall. They barely dock before Papyrus leaps onto shore.

“Come on, Sans, let’s go!” Papyrus grabs Sans’ hand and tugs him along.

“Boys—!” Papyrus doesn’t slow at Gaster’s half-exasperated, half-fond shout. Laughing, Sans lets Papyrus drag him along. They pass by old man Gerson’s shop, past the strange Temmie Village.

Papyrus skids to a stop as they reach a field of echo flowers. Striking a heroic pose, he shouts: “Papyrus is great!”

Hundreds of flowers repeat the compliment. Sans snickers at the sight of his brother growing proud at the sound of his own voice.

“Bro, will you be okay here?”

“I’m fine, Sans.” Papyrus crouches down, and starts to strike up a conversation with the flowers. Sans loves his brother, but doesn’t think he’ll ever understand his oddities.

Sans heads deeper into Waterfall, and pushes down the slight twinge of guilt. He’s not going too far. And Gaster should catch up to Papyrus shortly—it’s the same place Papyrus always goes. Besides, Sans really, _really_ wants to see the stars.

Sans reaches the stargazing room. With some relief, he notices there are no other monsters around to hog the telescope. Sans peers into it, too eagerly. The telescope goes into his eye socket.

“Shit.” His father would be furious if he heard him swear. The sensation of something inside his skull is exceedingly uncomfortable, as if he is constantly getting chills. Sans slowly extricates the telescope. He’s glad Papyrus isn’t here to see this; Sans would never hear the end of it.

Carefully, he puts his eye socket back up to the telescope. The sight takes his breath away, as it always does. Hundreds of stars glimmer down at him. Gaster told him they were just sparkling facets of rock, and deep in his soul Sans knows he’s right. But there’s still a part of him that clings to the belief that stars are made from the wishes of monsters.

“I wish we could leave the mountain and see real stars,” Sans murmurs. He tries to see if his wish has somehow manifested into a star, but it’s impossible to count the plethora of shimmering gems.

“Sans!” His peaceful moment is interrupted by Papyrus’ shriek. Not an excited shriek—one of panic and fear.

Sans rushes back to the echo flower patch. Papyrus is stumbling back from three other monsters. One is a tall cat monster; the second, a wriggling mop of tentacles; and the third, an otherwise nondescript creature with a large hinging jaw. Something about them seems off, unnatural, as they lumber towards the skeleton child.

Sans throws out several bone attacks—not strong ones, just enough to knock the monsters back a little.

Papyrus scuttles over to join Sans. Anger roars to life in Sans’ soul as he notices his brother is limping, the bones of his leg darkly bruised and broken. Papyrus clutches the sleeve of his brother’s raincoat tightly.

“Who are these guys?”

“I don’t know!” Frets Papyrus. “They—They just showed up. I thought they wanted to be friends, but then they…” Papyrus glances down at his injured leg.

The older monsters have recovered from Sans’ weak attack, and start to slowly move towards them again. What should he do? Their dad’s probably still talking with Gerson, and has no idea of the world of trouble they’ve found themselves in.

“Hold onto me.” Sans grabs Papyrus’ legs, hoisting him up in a piggy-back style. Papyrus stifles his cry of pain as his leg’s jarred, whimpering into Sans’ shoulder.

Sans darts past the three strange monsters, and for a brief second he thinks they’re in the clear—and then one of the monsters reaches out with a rubbery tentacle, wrapping the appendage around Sans’ ankle. He goes down hard, and loses his grip on Papyrus. Papyrus screams in pain, curling in on himself. He won’t be getting up on his own anytime soon.

Sans’ soul throbs in his chest. He summons a long bone to his hand and uses it to slice off the tentacle still clinging to him. The monster hisses, throwing more of their tentacles towards Sans. Sans raises up a wall of bones. The tentacles smack against the magic, coming away singed from the contact. The stench of charred flesh permeates the air.

“Don’t hurt them!” Papyrus begs. He props the upper half of his body up on his arms, staring up at Sans beseechingly. “Sans, _please_.”

“They hurt you, Papyrus.” That’s all the reason he needs.

Sans drops the wall of bones, surging forwards to take the monsters on head on. The cat monster scratches at him, Sans narrowly dodging the swipe. Part of him is panicking. He knows how pathetically low his stats are. One slip up and he’ll be gone. He’ll leave Papyrus behind.

That’s not happening. Sans struggles with the cat monster, dodging his attacks while waiting for his opportunity to strike. The cat swipes horizontally, at his skull. Sans ducks under the blow, and drives a bone right through his chest. The cat yowls, and Sans feels the monster’s soul crack apart beneath the strength of his magic. The cat shatters into dust. Most of it sinks into the marsh, but a good portion falls over Sans, particles lodging in the small indents of his bones and oh god some fell through his eyes and mouth, the dust is _inside_ him—

Where did the other monsters go? Soul cold, he whirls around. They loom over Papyrus, sweet Papyrus, who either can’t generate magic in his haze of pain, or is refusing to out of principle. Either way, he’s defenseless against a pair of monsters that want him dead. Sans bombards the monsters with bone attacks. Bizarrely, they go down easily despite their large HP, both disintegrating into dust after a few hits each. A shudder wracks Sans’ body, and he feels something in his soul shift. He feels…He feels…

SANS LV 2 HP 1 AT 1 DF 1

“No.” He whimpers, sinking to his knees. Papyrus needs him, but the magnitude of what he’s just done sinks like a lead weight in his chest. He can’t come back from this. Can’t take it back.

“Papyrus? _Sans_?!” Gaster shouts, voice fraught with alarm.

He reaches Papyrus first. He checks to make sure he’s alright. Papyrus is badly shaken, his leg hurt, but in time, he’ll recover. Gaster moves to check on Sans, but Papyrus latches onto his pant leg with a vice grip, unwilling to be separated for even a moment. Gaster scoops him up in his arms, and together they join Sans.

“Are you alright?” Gaster checks him over, and stiffens. Sans turns his head away, knowing that his father has seen the ramifications of what he’s done.

Sans shies away, disgusted with himself, but Gaster draws him into a hug, shared between the three of them.

“I’m so sorry, my sons.” Gaster tightens his grip on Papyrus as he strokes a soothing hand along Sans’ back. “I’m so sorry.”

~*~

Gaster pulls them from school permanently, and it’s really not as big of a deal as it probably should be. While Sans had been rather popular, Papyrus never quite succeeded in securing any friends. Papyrus never had any friends, and Sans is too drained to care about the ones he had—so neither of them miss going to school, not really.

When they’d gotten home that horrible day, the first thing Sans had done was run to the bathroom. He set the water scalding hot, sat under the spray, and scrubbed at the dust on his bones enough to sand down sections of the bone itself. After an hour Gaster forced the door open. Sans, limp and passive, let him heal what he could. Gaster then bandaged the light burns and patches of irritated bone, saying nothing.

After that flurry of activity that first night, Sans effectively grinds to a halt as a living, breathing monster. He lays in bed all day. He doesn’t speak, only eats when Papyrus pushes the food to his teeth. Papyrus tries everything to get Sans to talk to him. He tries to pretend nothing is wrong, asking for help with his junior jumble. He brings astronomy books he scavenged from the dump, showing Sans pictures of the stars. He screams and rants and cries, saying things he doesn’t mean, trying to spark an angry comment.

But every night, no matter what Papyrus says during the day, he climbs into bed beside Sans. Papyrus whispers to him how great a brother he is, how nothing was his fault, until he can’t keep his eyes open any longer and he drifts off.

Sans wants to push him away, but he can’t even muster the energy for that. He’s truly a pathetic, wretched creature. Gaster hasn’t visited his room, not once, and Sans doesn’t blame him.

“I don’t know how to help you.” Papyrus confesses one night. He sniffles softly, unshed tears gathered in his eye sockets. It’s not his fault. Sans can’t be helped.

It’s something of a relief when, a month or so later—it’s hard for Sans to keep track of exact time—Gaster starts taking Papyrus to the Lab with him during the day. When Papyrus is gone, Sans fully focuses on how uncomfortable he feels in his own body, the scratching, itching sensation that he can never escape.

Every evening, Papyrus feeds him and chatters on about his day in the Lab. He’s been working with their dad on a very big project, something meant to provide power to the entire underground.

“Also, Father has been giving me magic lessons every morning.” Papyrus admits. “He told me I needed to learn how to properly defend myself, so you’d never have to…” Papyrus clears his throat, changing tack. “And I’ve finally gotten the hang of a blue attack.”

Good job, bro. I’m proud of you. The praise gets clogged in his throat, just like everything else he’s tried to say. Amazingly, his brother never falters, providing a constant stream of one-sided conversation while he’s awake, hugging Sans tight to his chest when he sleeps.

Everything changes one night when Papyrus enters their room shaking and dusty. He climbs into Sans’ bed, clutching at his brother’s shirt. For the first time since the incident, Sans initiates a hug, pulling Papyrus closely to him. For the first time since the incident, Sans speaks, his voice hoarse and croaky with disuse.

“Papyrus, what happened?” He pulls apart from his brother so he can look him over critically. His bones are strong and sturdy, intact, as is his soul. This can only mean—

“Sans, Sans. I didn’t want—I didn’t. But Father said, Father…” Papyrus clutches him tightly, sobbing. With dread, Sans checks his brother’s stats.

PAPYRUS LV 2 HP 240 AT 8 DF 8

Sans’ anger and indignation simmer beneath the surface as he helps Papyrus change into fresh clothes, helps him gently scrub the flecks of dust from the grooves of his bones. Once Papyrus falls into a fitful sleep, Sans extricates himself from his brother’s hold, careful not to wake him.

Though the door is shut, Sans can see that the light is on in his father’s study. With a wave of his hand the door is blasted open, quivering on its hinges. Sans steps inside.

Gaster sits at his desk, unflappable. He finishes the equation he was writing and sets down his pen, staring at Sans levelly.

“Well, aren’t you a sight for sore eyes.”

Gaster has always been calm and collected, but something about him seems different. He’s more cold. Indifferent. Sans has missed a major shift in his father’s temperament—or was it always there, beneath the surface, and Sans simply hadn’t noticed?

“What have you done.” His eyes are empty pits.

“Sans.” Gaster says, somehow packing the one short syllable with an astounding amount of condescension.

“I know Papyrus. He never wants to hurt anyone. He would never increase his level by choice.”

“And what of you? Did you level up purely through choice?”

Sans swallows. It had been out of necessity, desperation. When looked at objectively, Sans supposes he _did_ have a choice—to fight, or let Papyrus and himself get killed. There was only one choice for him in the end, but it was still a choice he made.

“It is unfortunate, but it is necessary. For Papyrus to survive in this world, he needs to be able to defend himself.”

“Why would anyone ever attack him?”

Gaster gives him a flat look, that says he’s being particularly thick. “You two were already attacked, were you not?”

“Yes, but—”

“And what of when a human falls down into the underground?”

“ _When_?”

“When.” Gaster stresses. “It’s inevitable. There are far too many of them for it to never happen. Do you have any understanding of how strong humans are?”

“I’ll protect him. I’ll protect Papyrus, so please, just—leave him alone.”

Gaster is skeptical. “How do you expect to do so? He’s already surpassed you.”

“I’ll—I’ll…” Sans flounders. What can he say?

“…If you’re truly serious about this, there is a side project I’ve been working on that may be of some value. As a counterbalance to your low stats, I can give you additional power through scientific means.”

“Anything.” Sans promises him. “Anything, just. Please promise to leave Papyrus out of it.”

“That will depend entirely upon you.” Gaster returns his gaze to his work, picking up his pen. “Meet with me tomorrow morning and we’ll get to work.”

The dismissal in his tone is plain. Sans leaves the room. Once in the hallway, he expels a huge gust of breath, tension draining from his body. Returning to his shared bedroom, he climbs back into his bed with Papyrus. His brother rolls over and latches onto him in his sleep, drawn to his body heat. Sans will fix this. He’s awake and aware now. The burden of responsibility will shift back to him, as it should.

“I’ll protect you, Papyrus.” Sans vows. “No matter what.”

~*~

The sun rises, and Sans is strangely awake before his brother. Well, perhaps it isn’t too odd, considering what Papyrus had gone through the night before. In his sleep Papyrus looks peaceful, unharried by nightmares. Sans is glad.

He makes the trek from New Home to the Lab in Hotland, where his father works. Monsters give him friendly waves as he passes by, which he returns tentatively. His head buzzes with confusion, conflicting ideals. Aside from the trio that attacked him and Papyrus, other monsters on the whole have been nothing but kind. Is his father right? Is Sans being too naïve?

Sans enters the Lab. The security guard waves him through without checking his ID; Gaster has brought him and Papyrus to the Lab frequently enough for the regular staff to become familiar with them. He navigates the winding hallways and series of elevators and ultimately reaches the Royal Scientist’s office. Sans steps inside, and tries not to let his nervousness show.

Gaster isn’t there. Sans’ attention is drawn to a glowing red concoction set on his father’s desk. It bubbles, lit underneath by a small simmering flame. Sans approaches it cautiously, curiously.

“What is this?” He wonders.

“That, Sans, is the solution to everything.”

Sans jumps as Gaster enters the room, shutting the door firmly behind him.

“The King has put me to work designing the Core. A waste of my time.”

“But why?” Gaster looks annoyed at being interrupted, so Sans explains himself quickly. “A concentrated power structure would be ideal.”

“My goal is not to sustain life underneath the mountain.” Gaster chides him, as if he should just know this. “My goal is to get us _out_.”

Sans swallows. Gaster moves over to the beaker. He pours its contents into a metal cup, and hands it to Sans. Sans holds the cup with both his hands, staring down at it. Smoke curls up from the red liquid, the smell far from pleasant. Sans has a moment of doubt, of hesitation. He trusts his father, but. What will this do to him?

“Sans.” He looks up to meet Gaster’s gaze. “You want to see the stars, don’t you?”

Sans nods.

“And you want Papyrus to be happy.”

“Of course.”

“Then, for the good of Papyrus, for the good of all monsterkind, you must do this.” It sounds nice when his father puts it that way, but still. Part of him is frightened. Why is his dad making him do this? Why can’t he test it himself?

He shakes his head. That doesn’t matter now. If he doesn’t do this, then Papyrus might have to. Screwing his eyes shut, he tips the formula down his throat. He’s barely finished when it reacts fiercely with his own magic. Sans cries out, dropping on all fours. The cup falls from his hand and rolls across the floor. He simultaneously feels like he’s freezing solid and burning alive. His magic flares up, trying to push the substance out of him.

“ _Don’t_ bring it back up.” Gaster commands. Sans swallows hard, clamping a hand over his teeth. He feels his eyes turn blue, brighter than ever before. Excess magic trails out of the sockets, evaporating in the air.

“It hurts!” He howls. He feels like his body is trying to stretch itself out, split apart from the inside. “It hurts, it _hurts_.”

Gaster crouches down before him, watching him closely as he thrashes. Sans grasps loosely at his father’s pant leg.

“Dad, Dad, please make it stop.”

“It’ll be over soon.”

It’s not. Sans isn’t sure how long he lays there, twitching and spasming as something inside him reconfigures, but it feels like an eternity. But finally, the pain tapers off. His body aches, his soul shining weakly in his chest.

“How do you feel?” The question is clinical, not concerned.

“…Better.” Sans grunts out.

“Can you tap into your magic?”

“Yeah.” Sans can feel the large reservoir of magic at his disposal, now no longer volatile.

“Activate it.”

Sans shoots him an incredulous look. He wants him to summon magic? Now?

He stands nevertheless, bones creaking in protest. Sans calls up his magic, sensing its blueish aura flare up around him, small bone attacks forming by his hands.

“Interesting. It appears to have siphoned off the surface layer of your magic.”

Sans catches sight of himself in the reflective metal of a nearby lab table. With some dread he notices that the light in his right socket has been extinguished. The magic doesn’t feel gone, exactly. Just reallocated.

“There certainly was a reaction of some kind.” Gaster seems pleased. He waves him from the room. “Go home and rest. We’ll start testing tomorrow.”

He wants to ask what exactly he just drank, but Gaster sweeps from the room, presumably moving onto the next project on his schedule.

“Guess that’s that, then.” Sans mutters to himself, and heads home.

The walk home is slow (on account of his lethargic shuffling) and uneventful.

The door creaks as he steps back into their quaint house. He hears thudding footsteps above and then Papyrus is there on the steps, panting, tear tracks down his face.

“Papyrus?” Sans starts to approach him, slowly.

“Sans.” He whimpers, running over to envelop him in a hug.

“Bro, what’s wrong?” Sans curses himself. That was a dumb question.

“I couldn’t find you.” Papyrus’ bones rattle. “I couldn’t find you, or father, and I thought…I thought you left me.”

“Papyrus, no.” Sans admonishes him softly. “Why would you think that?”

“You know why.” Papyrus retorts. “I messed up. I was bad.”

Sans swallows. He’d tried to pry the truth of what happened out of him the night before, but Papyrus wouldn’t tell him.

“Whatever you did, it doesn’t matter.”

“Of _course_ it matters! I can’t take it back, can’t—”

“If that were really true, if a monster became something horrible after—after gaining one level, then why have you been nice to me?”

Papyrus’ mandible quivers. “That was different! You didn’t mean to do it, you didn’t have a choice…”

“I don’t know the specifics of what happened, Papyrus. But I know you’d never enjoy hurting someone else.”

Papyrus curls tighter into the embrace. Sans lightly taps their skulls together.

“I don’t care what happened, Pap. You’re my brother and I’ll always love you.”

“I love you too, Sans.” Papyrus’ reply is muffled by the fabric of Sans’ shirt.

“No more tears now, okay Pap? You’re killin’ me, here.”

~*~

The next day finds Sans in the lab again. He tries to stand still as Gaster tapes multiple sensors to his skull. He isn’t quite sure what his father expects of him. Aside from the slight drain of his magic, the solution didn’t seem to do much else to him. Papyrus is present, too. He smiles timidly at him from behind Gaster’s shoulder, and Sans gives a small grin back.

Gaster, once content with the numerous sensors plastered to Sans’ skull, leads Sans through the lab to a testing room. He gestures for Sans to enter from one side, while he and Papyrus enter the other half, which is protected with a thick sheet of glass.

Sans rocks back and forth on the balls of his feet, watching Papyrus help Gaster set up various instruments. Finally, Gaster presses a button on his console, and his voice crackles over a loudspeaker:

“You have been given a serum that instills you with a wholly unique power. In layman’s terms, you can teleport.”

“ _Teleport_?” Sans balks at the idea. It sounds like something out of the comic strips on the newspaper, not actual science.

“Don’t overthink it. All you have to do is will yourself to be somewhere else, and you will be. Now, teleport over to the other side of the room.”

This is insane. Impossible. Nevertheless, he does as his father requests. He stares at the other side of the room, and wills himself to _be there_.

….Nothing happens. Sans glances at the booth. Gaster watches him impassively, Papyrus, with a small measure of concern.

Sans tries again.

Again.

Once more.

Ten agonizingly long minutes crawl by this way.

“It’s _not_ complicated.” Gaster is irritated. Papyrus wrings his hands.

“What am I supposed to be doing here? ‘Cause staring at the wall isn’t doing anything.”

“You’re not trying hard enough. Keep going.”

With a huff, Sans tries again. His skull and palms are starting to wet with panicked sweat. This is accomplishing nothing. Several more moments pass in this fruitless manner, and then Gaster rises from his chair.

“Alert me when he decides to start working.”

Gaster leaves the room. The two brothers stare dumbly at each other through the glass for a beat, and then Papyrus leaves the reinforced half of the room to join Sans.

“Can you really teleport?” There’s an edge of excitement to his voice.

Sans shrugs helplessly. “I don’t know. I don’t think so.”

“You don’t feel anything when you try to do it? Nothing at all?” Papyrus prompts him, trying his best to help.

“No, nothing.”

“Hmm.” Papyrus taps his foot for a moment, then brightens.

“You must just be trying too hard!”

“Bro, I don’t think that’s it.”

“Nonsense! Just try to relax.”

Sans takes measured breaths, doing as Papyrus says. He doesn’t let stray thoughts clutter his mind. He just pictures the other side of the room. He wants to be _there_.

Sans opens his eyes again. Papyrus is still standing in front of him.

“It didn’t work.”

“Oh.” Papyrus deflates.

The door to the room suddenly bangs open, making them both jump. Gaster thunders in, red flickering in his eye sockets. Sans feels his soul turn blue, sees Papyrus’ go blue as well. Gaster pins Sans fast to the near wall, while he flings Papyrus to the other side.

“What are you doing?” Sans strains against the blue technique, but can barely lift his head from the wall.

Gaster summons several bones, that look sharp and deadly. He launches them at Papyrus, who’s still dazed, unable to protect himself.

“Stop it!” Sans flings his own magic forward as a shield, but knows it won’t make it in time, it _won’t get there in time_ —

Gaster’s attack halts less than a fraction of an inch from Papyrus’ body.

“I suppose you weren’t lying after all. You really can’t teleport.” Gaster muses.

The Royal Scientist releases his hold over his two sons. As Papyrus picks himself up again, rattled, Sans sets upon Gaster.

“What were you thinking?! Papyrus could’ve been killed, and all for your stupid experiment!”

Gaster strikes him across the face with a resonating smack, hard enough to send him sprawled onto the floor. Making a soft noise of sympathy, Papyrus helps Sans back into a sitting position.

“Your stats don’t increase, and now you can’t do this _one simple thing_.”

“Dad.” Sans whimpers.

“Pathetic child. You’re not worth my time or effort.” He gestures to Papyrus. “Get him out of my sight.”

Sans bows his head in defeat.

~*~

After Sans’ failure, Gaster all but moves into the Lab. That suits Sans just fine. Papyrus acts as a sort of go-between, going in to work with Gaster bright and early every morning, and returning home to Sans well after the sun has set.

Sans has the freedom to do whatever he wants; he spends most of his time curled up in front of the television. Some new robot is trying to get his big break, making small guest appearances on various shows. Every now and then Sans shuffles out behind their house to practice his magic, lest the build-up of excess energy become uncomfortable. When he feels ready to suffocate from boredom, he meanders around the streets of New Home, doing whatever strikes his fancy at the time. He charges all his expenses in Gaster’s name—no point in being a screw up if you don’t go all the way.

Some nights, Papyrus doesn’t come home. Those nights, Sans lies in his bed, staring up at the ceiling, dread squeezing his soul with its cold, slimy fingers. Every time, he convinces himself Papyrus is never coming home, killed or maimed from some horrific experiment that went wrong at the lab. Every time, he feels foolish and stupid when Papyrus stumbles inside with the sunrise, tiredly explaining why he was held up. It amazes Sans, how Papyrus has adapted to function with only brief snatches of sleep.

But most nights, Papyrus does come home. He always brings things home from the lab—blueprints creased and folded in his pocket, new equations scrawled into notebooks. Papyrus always chatters on about how his days go, but he’s always careful to mention the experiments and projects only, never their father. He’ll bring home sheets covered in their father’s small, jumbled penmanship, and Sans helps Papyrus parse the meaning. Some nights, after Papyrus falls asleep, Sans goes over to his brother’s blueprints and notes, making his own small additions. Sans might be a failure to his father physically, but at least he’s still good for _something_. He writes his additions in faintly, so Papyrus can go over them in the morning in his own hand. Neither acknowledge it.

Rarely, Sans is up early enough in the morning—or hasn’t yet fallen asleep—and waves Papyrus out the door. The rush of jealousy he feels wracks his bones, makes him nearly ill. But he prides himself on never showing it. It’s not Papyrus’ fault, after all.

Years pass. Gaster with the assistance of Papyrus (and Sans, unwittingly) as well as his other lab assistants, completes the Core. King Asgore is thrilled, and now Gaster is given free reign to do as he pleases with his time. Of course, the Royal Scientist launches an official program to breach the barrier.

Papyrus informs Sans that Gaster has given up on teleportation as an avenue; instead, he’s starting an entirely new project, his tour de force. Papyrus starts to clam up when it comes to precisely what they’re working on. The steady stream of blueprints and equations slows to a trickle, for when Papyrus is truly, desperately stuck on a problem. It’s not enough for Sans to grasp the full extent of what the project entails.

Papyrus grows more haggard, and Sans wants to inquire, to press, to know what the hell’s going on—but he doesn’t say anything. He doesn’t want to push, too afraid he might push Papyrus away. He picks up a nasty habit of cracking his knuckles when he feels anxious.

Sans is 16, lazing on the couch before the television, when the doorbell rings. Sans frowns; he didn’t order any takeout. Maybe the mailman is confused about a package delivery or something.

Sans opens the door.

“Hello—”

Sans stiffens, greeting dying in his throat. It’s Gaster. He looks a little older, more rough around the edges. But his eyes still pierce Sans with the same cool stare.

Sans is uncomfortably self-aware. His clothes are covered in food crumbs, mottled with random stains. He hasn’t showered in ages.

“Come with me.” Gaster says, simply. He turns on his heel and leaves. Sans hurriedly grabs his keys, locks the front door, and catches up to him.

Sans is taken to the Lab, as he suspected he would be. However, he’s confused as to why. Gaster leads him through a maze of hallways he hasn’t seen before until they’re in a workshop of sorts. Wrenches, soldering irons, and other various tools are scattered throughout the room. Sans’ gaze is drawn to the center of the room, where a strange-looking machine rests. It has a tube-like compartment, for someone to climb inside. The bottom half is filled with so many buttons and dials it makes Sans’ head spin.

Gaster walks over to it and keys in a code. The top half of the tube hinges open with a slight hissing noise. He becks Sans closer.

“Get in.”

But Sans is hesitant. “What does it do?”

“You don’t need to know that. You just need to climb in.”

Sans takes a step back. “Yeah, you know what? No.”

Gaster stills. “What did you just say to me?”

“I said no!” Sans shouts. “I don’t know what that thing is, or what will happen if I go in it. I want no damn part of this. You can’t just bring me into this stuff out if the blue because you want me to be your guinea pig.”

Sans gasps as his soul is turned blue. Gaster forcibly flings him into the machine, shutting the glass casing over top of him.

His breaths come in sort gasps. The machine is too small. He can’t do this, he can’t—he pushes weakly at the glass in front of him, but it doesn’t budge.

Gaster still keeps him pinned by his soul, but returns to his work, fiddling with the machine’s components. Sans feels the power switch on, the machine humming to life around him.

“Is that Sans?” Papyrus skids into the room, looking alarmed.

“Papyrus. Excellent timing. I’m nearly ready to begin.”

“Y-You can’t!”

“Oh?”

“Please, father. He—It—The numbers are all wrong!”

That makes Gaster pause. “What was that?”

“The figures, the equations, I—” Papyrus’ gaze cuts to Sans with desperation. “I can’t see very well! Especially not your handwriting. I—I’ve been taking it home for years, and Sans helps me figure it out, but I haven’t in some time. You can’t activate the machine yet. It’s not safe.”

Gaster is livid. His arm snaps up, and his powerful magic is flung forth, hitting Papyrus square in the face. Papyrus’ shriek of pain mixes with a horrific cracking sound.

“Papyrus!” Sans’ cry is muffled by the glass. Papyrus falls down, so Sans can’t see what happened exactly, but he knows it can’t be anything good.

Gaster returns to operating the machine. “Let this be a lesson to you, Papyrus. This is what happens when you lie to me.”

Gaster flicks a switch. Blackness crawls across Sans’ vision. He doesn’t want this, whatever it is. He wants to live, he wants to get _out_ —

There’s a flash of light, and Sans is gone.

He blinks, reorienting himself. He’s by the door of the room Neither Gaster nor Papyrus see him, fixated as they are by the machine. Did he just—?

“Sans!” Papyrus wails, voice full of pain and anguish.

Gaster ignores him, reopening the machine, peering inside.

“Not a trace to be found.” Gaster gives a short laugh of triumph. “It worked!”

“Did it?” Sans growls.

Gaster whirls to face him, but he’s already too late. Sans uses his father’s favorite attack against him, turning his soul blue. He throws Gaster into the machine, slamming the cover down on top of him. For the first time in his life, Sans sees his father’s veneer crack. He looks truly frightened.

“Sans, you’re making a mistake—”

“Let’s see how you like it.”

Sans flicks the switch. His father has no nifty teleportation power to fall back on.

Sans watches as his father’s body starts to melt and transform, skull splitting apart, mouth gaping wide, frozen in a silent scream.

And then he’s gone. Vanished. Not even a black stain of him remains.

“Holy _shit_.” Sans breathes. Did that really just happen?

Papyrus’ groan of pain shakes him from his stupor. Sans hurries over to his brother’s side, wincing as he sees the damage left behind from Gaster’s rage—a large crack runs down Papyrus’ face.

“Are you alright?” Sans reaches out to comfort him, but Papyrus smacks his hand away.

“Don’t touch me.” Papyrus snarls, eyes blazing red. Sans flinches back. “Don’t you ever touch me again.”


	5. Purpose

Sans throws open the door to Grillby’s, hard enough that the door slams against the wall. The only ones inside are a drunk bunny monster, a pair of birds, and the fire monster himself. Sans must look a bit frightening to them, Papyrus’ scarf around his neck, the lights in his eye sockets bright and manic.

“Wow, this place sure is _dead_ tonight.”

Out of the corner of his eye he sees the bunny flinch. They all want to run. But none of them want to draw attention to themselves through movement.

Sans hauls himself up onto his usual barstool. Grillby pours him a drink. The usually unflappable monster is actually shaking, some of the glass’ contents sloshing over the side as he hands it to Sans. Once he accepts the drink, Grillby moves to retreat to the kitchen.

“Why don’t you stay a while, Grillbz? Not in the mood much tonight for a burger.”

The flame monster reluctantly returns, and starts to polish a glass to hide his nerves. Any other night, Grillby could probably take him in a fight. But tonight, he’s the most dangerous thing in the underground.

With his weak constitution and small mass, it doesn’t take long for Sans to get sloshed.

“I dunno what I’m supposed to do now.” He confesses. “I really don’t. My ticket to the past just up and ran off. Tell me, Grillbz. How the fuck do flowers even run?”

He gets some amusement from watching Grillby struggle to pick apart his ramblings.

“…I am sorry, Sans.”

“For what?” Sans swallows down another drink. It leaves a nice burn behind.

“…I’m sorry about Papyrus.”

Several bottles shatter on the bar shelf. One of the patrons gives a frightened squawk.

“The Boss is fine. Nothing in this timeline fucking matters, got it?”

The bartender nods along. “…Another?”

“Just leave some bottles and get out of my face.”

Grillby dutifully sets the most expensive spirits before him. He inches away from Sans, and once his hand grasps the door handle to the fire exit he’s gone. The patrons take this as their cue to leave as well, and sprint from the bar. Sans lets them go, even though it doesn’t matter either way if they’re alive or dead. Because one way or another, this timeline _will_ reset. There will not be a world where Papyrus does not exist.

Sans grabs two of the bottles by their necks and hops down off the barstool. He tilts to the side, ribs digging into the side of the dogs’ usual table. He stumbles over the other way to the booths, and slides his body onto the sticky green vinyl. With his house destroyed, this’ll have to do for a bed. He’s slept in worse places. He only manages a few swigs form the bottles before he’s out cold.

~*~

Morning finds him in more or less the same position, with pain blossoming in his head from the drink, and his spine from his sleeping condition. He blearily notices that the bottles had tipped over and spilled their contents in the night; he must’ve set them down wrong.

Sans chuckles a bit, even as it aggravates his headache. A good portion of the liquor has undoubtedly sunk into the wood, ruining it. Ah well. Grillby would only have to be mad about it for a few days.

Sans picks himself up, carefully stepping over the puddles and leaving the bar. He squints in the midday glare. No one was in the bar when he awoke. Perhaps Grillby and the regulars plan to stay away for a few days in case Sans planned to linger there.

But Sans shuffles away from the bar, back to his own house. He circles around the wreckage, to the shed behind the house. Though a few shingles and beams have fallen from the main house onto the shed, the tiny building still stands just fine. He steps inside, not quite sure what he’s looking for. All this junk is ancient, unbothered for years.

Everything about his childhood is….disturbingly fuzzed over, now that he thinks about it. Probably too much continual head trauma. He remembers living in New Home, and there was some involvement with the Lab. When he and Papyrus moved to Snowdin, they sold most everything. But they saved a few boxes of important-looking (but monetarily worthless) documents. They shoved them in the tiny shed and left them to collect dust. Both of them had thought them meaningless, but if they have to do with whatever work went on at the Lab, maybe it’ll give him some clue of what to do next.

Sans looks around the room. Nothing but boxes and boxes of crap. He grabs the nearest box, sits down, and starts rooting through its contents. The feeble bud of hope in his chest quickly wilts to irritation. All these papers are written in some bizarre, illegible language.

What makes his incomprehension worse is that he feels like he _should_ know how to read this, but every time he feels like he’s close to grasping something, it sleeps right out of his reach.

Sans shoves the box away, annoyed. He grabs another and begins to pick through it, looking for something, anything, that might help.

Sans is flipping through the box, about to give up, when he finds something that makes him pause. On the front of a journal is Papyrus’ name, written in his looping scrawl. Sans opens it to the first page. Papyrus had written the date at the top—the journal is nine years old. Jesus, they were only kids then.

He thumbs through the journal, growing more confused by the minute. The equations he can make no rhyme or reason of, but Papyrus had also written his thoughts about the numbers, trying to work through them logically. From what he can gather, everything in here is about the design of the Core.

Sans has never thought of Papyrus as dumb, not for an instant. A fool could never climb the ranks as he had. Brute strength is not enough to propel oneself to the top. Sans can recall many powerful, overconfident monsters who fell to an unexpected knife in the back.

But even though Sans knows his brother is wickedly clever, Papyrus has more of a mind for strategy and tactics. He’s never been known for his scientific knowledge—and yet this is unmistakably his penmanship. Sans knows, because he always looks through his brother’s reports to the captain to double check—and then triple check—for spelling errors. With Papyrus’ poor vision, it’s difficult for him to look over his own work.

Sans pauses a few more pages into the journal, finding something even more perplexing. His own handwriting, crammed into the margins of the page, additions to Papyrus’ work.

“What the hell?” He traces the writing with one finger bone. This could only be his writing. Even the p’s and q’s are curved the way he always does them.

So apparently Papyrus _and_ himself had been capable of high level science as children, and then just…forgot?

No. Something’s going on here.

Sans tucks the notebook into his jacket and teleports to the basement level of the Royal Scientist’s lab. If there is any extra information about this stuff, this is where it’ll be.

The lights are off, and Sans stumbles around in the dark like an idiot until he remembers he doesn’t have to. He summons his magic, and a glow emanates from his eye socket, catching the room in red light. He finds the nearest light switch and flicks it on. Something behind him hisses at the sudden glaring brightness.

Sans turns to see one of the amalgamates gamely plodding over to him. At least it’s Endogeny. Of all the creepy fucks, this one weirds him out the least.

“Hey there, pup.” The beast takes his words as an invitation to come closer. Its tongue lolls out, drool flicking onto Sans’ sleeve. Its white, amorphous body disturbs him, faintly calling to mind Papyrus’ melted form. He shoves its wet nose away from him, ignoring its whines.

Sans meanders for a time around the dim hallways of the Lab, searching for anything useful. He finds little but Alphys’ old, abandoned experiments, along with bowls and bowls of stale dog food.

His feet carry him to an office, and he opens the door hesitantly. He can’t place why, but something about the office makes him uneasy. The furnishings are sparse, minimalistic. Cobwebs and dust have claimed the abandoned room. He goes over and starts to snoop around the desk, pulling open the top drawer.

Inside, a row of folders, almost too neatly organized. There are tabs at the top, but the labels are written in the same language of those symbols. Is this some sort of secret code scientists use to keep their work hidden? Inspection of the files within proves futile. The juxtaposition of the bizarre language with complex equations makes his head swim.

There’s only one monster who can give him the answers he seeks. Sans sets the folders down and teleports to the surface level of the Lab. But to his surprise, Alphys is absent, the monitors playing to an empty room. She must still be asleep, then.

Sans tromps up the steps to the Royal Scientist’s sleeping quarters.

He stops short at the foot of the bed. Alphys is curled up in the embrace of Captain Undyne, both snoring loudly in their sleep.

“God fucking damn it.” He mutters.

Sans could try to extricate Alphys quietly, without disturbing the captain, but fuck it.

He summons a blaster. A high-pitched whine pierces the quiet as the skull charges an attack. It’s enough for the captain to snap awake. She instinctively grabs Alphys, and rolls out of the bed with the squawking dinosaur a second before Sans’ blaster fires at the bed.

The captain summons a deadly spear, brandishing it at him as tufts of bed stuffing drift down around them. Even without her armor, in scant sleepwear, she looks like she could break his femur in half with a glare.

Then she does a double take.

“ _Sans_?”

“The one and only.”

Captain Undyne’s gaze darts around the room, before coming to a stop at the scarf still around his neck. With her spare arm, she guides Alphys behind her.

“Is Papyrus about to attempt a grand entrance or something?”

Alphys flinches at the sight of Sans’ frightening smile. “Papyrus is dead.”

The Royal Scientist gasps; she must’ve been otherwise occupied, to not notice Papyrus get attacked by the canine unit.

Captain Undyne bears her teeth. “And what? You’re here to submit your application for his position?”

Sans shakes his head. “I’m not here for you. I need your little girlfriend, hiding behind you.”

Alphys cowers as Captain Undyne launches at Sans with a roar. Sans nimbly dodges the numerous spears thrown his way. Maybe he gained something from his grueling training sessions with Papyrus after all.

“Come on, captain, this is uncalled for. I’ll be gentle.” Sans goads her. The stupid fish falls for the bait.

“You won’t touch her!” Captain Undyne’s attacks grow more powerful, but also more uncontrollable as her rage builds.

One of the spears skims dangerously close to his face, the heat from the attack singing his cheekbone.

“Enough already.” Sans encases Captain Undyne in a cage of bones, so densely built she can hardly see through the rows of white.

“ _Sans_!” Captain Undyne bellows. She slams her fists on the bars, but they hold steady.

Sans can’t help a short laugh at her expense. She’s like a child in a crib, throwing a tantrum.

“Don’t worry, captain.” Sans saunters over to Alphys, who’s now a quivering, blubbering mess. Pathetic. “I’ll bring her back when I’m done.”

“NGAH!” The captain’s furious strength is enough to shatter the magical attacks.

She stares Sans down, her fists smoking slightly, skin split open at the knuckles. Even though Sans knows he has the advantage, a fear crawls down his spine.

Captain Undyne lunges at him, but she doesn’t have Sans’ agility. He snaps his hand out and four sharpened bone attacks pierce her limbs, pinning her to the wall. Her HP plummets dangerously low, and she blacks out from the sudden wall of pain.

One of Sans’ blasters idles by Captain Undyne’s slumped form, standing guard. Sans turns back to look at Alphys, who’s still ducking her head.

“What, no “don’t hurt her”? Nothing?”

Alphys tries to speak up, but nothing comes out, and she closes it again, shamefully.

“Christ, you are selfish.”

Sans grabs her wrist and teleports them both into the downstairs office. She looks around, confusion and fear warring for dominance on her face.

“H-How did you—?”

“Look at these.” Sans interrupts her, shoving one of the files at her.

Alphys puts on her glasses and fumbles it open, peering inside.

“Um, I c-can’t read this. I’ve never seen this language before.”

“The previous Royal Scientist must’ve written it. Who were they?”

She blinks. “I-I don’t know.”

“You don’t _know_?”

“No, I do! I-It’s just hard to remember, exactly. There wasn’t a Royal Scientist for years and years before I took over.”

“That doesn’t add up.” Sans brandishes the journals from the shed before throwing them onto the desk. “The Core was only built about a decade ago. You should’ve been trained by him. You should have at least _heard_ of him.”

Alphys can only shrug helplessly.

Sans kicks the corner of the desk in frustration. Alphys picks up one of the journals and buries her head in it. This trip was a waste. He’s learned nothing useful, and pissed off the captain.

“W-Wait a second!” Alphys pipes up, returning Sans’ attention to her. “I can read the numbers in this one just fine. Some of this stuff is about the Core, coolant regulation and—”

“Anything besides that?” Sans cuts in.

Alphys keeps searching until she’s near the end of the journal. “…These are the dimensions of the barrier. And something about…time? Time travel?”

Sans slots the clues of the puzzle together in his mind.

“They were trying to figure out a way around the barrier.”

“With time travel?” Alphys is skeptical.

He grabs her wrist again, and she flinches, expecting to be struck for her words. But he merely teleports them both and deposits her in front of Captain Undyne, still out cold. With a wave of his hand, the bones dissolve, and the captain slumps, boneless, to the floor. Sans recalls his blaster as well.

“You can still save her. Or don’t. I don’t care.”

Sans teleports from the room before Alphys can question him further, now outside the Lab. He breathes deeply, inhaling the smoky fumes. Papyrus had always complained of the stench, but Sans enjoyed it.

He hears a rustle of leaves, something out of place in this land of magma.

“I was just on my way to find you.” Sans says, drawing Flowey out into the open.

Flowey fixes him with the most baleful glare he can muster. It’s not all that impressive.

“You could have killed her!”

“How did you even see that? Were you hiding in the fuckin’ vents?”

“Sans.”

The skeleton shrugs. “What more do you want from me? I could’ve killed her, but I left Alphys to patch her up. That hardly makes me the underground’s worst monster.”

“Why did you even attack them in the first place?”

“I needed information. Didn’t expect fish face to be there.” Sans crouches down so he’s closer to eye level with Flowey. “Do you want to hear my solution, or not?”

Flowey lets the point drop, and nods.

“We need to go back.”

“Sans, we’ve tried that—”

“Let me finish. We need to go all the way back, before any of this happened. The previous Royal Scientist—they were working on a way to break the barrier. I’m sure teleportation could help them out.” Sans leaves out the fact that he and Papyrus had made notes on the project as well. He still isn’t sure what to make of that. “We break the barrier, this all goes away.”

Flowey frowns, not quite getting it. “What do you mean?”

“Why do you think monsters are like this?” Sans gestures to the rock ceiling above them. “Being forced to spend an eternity squashed next to each other isn’t a good time for anyone.”

Flowey still looks uncertain.

“Can you do it? Can you bring us back to nine years ago?”

“I can. I can go back to any time after I was made into this. It’s just…” Flowey hunches, avoiding Sans’ gaze. “Traveling so far back is different than resetting a few days or weeks.”

“Different how?”

“You want to keep that body when we go back, don’t you? It’s harder to shift bodies back, along with our consciousness.”

“But you can do it.”

“Yes.” He takes a moment to gather himself, then looks up at Sans, stem straight. “Let’s do it.”

“What do you need me to do?”

“Let me see your arm.”

Sans hesitates, but the flower monster’s eyes are wide and innocent. Against his instincts, he offers Flowey his right arm. Flowey stretches up, his leaves curling around Sans’ hand. Flowey hoists himself up from the soil. Sans grits his teeth as Flowey winds himself around Sans’ arm, securing himself. When the flower’s roots start creeping up to his shoulder he draws the line.

“That’s far enough.” He snaps.

The ends of the roots curl back instantly. “I’m sorry.”

“Would’ve preferred to put you in a pot.”

“We can’t run the risk of being separated. I don’t know what would happen then.”

Flowey pokes his head out of Sans’ sleeve, craning his neck up to look at him.

“Are you ready?”

“As ready as I’ll ever be.”

“Alright. Remember, don’t let go.”

Flowey closes his eyes, with a look of intense concentration on his face. For a long moment nothing happens, but then—

Darkness.

Silence.

Sans tries to speak, but no words come out. He tries to readjust his grip on Flowey, but he can’t feel the small monster wrapped around his arm anymore. He can’t feel anything, not the jacket around his shoulders, not the boots on his feet.

What the fuck is happening? Is he trapped here now, wherever “here” is, his senses locked away?

But no. He must still retain his sight, because something is shifting in the darkness. It’s barely perceptible, but it’s there; Sans sees the thing move closer to him. He wants to run, but he’s incapable of doing anything. He can’t even close his eyes to what’s coming.

And then he’s spat out on the crusty ground of Hotland. Sans gasps, shaking. Flowey pokes his head out of the jacket sleeve, looking at him with concern.

“Are you alright?”

“Did you see that?” Sans rasps.

“See what?”

“That…that _thing_.”

Flowey tilts his head, confused.

“There wasn’t anyone in there besides us, Sans. There couldn’t have been.”

 “...Right. Guess my mind was playing tricks on me.”

Sans picks himself up, and the two companions stare up at the looming building before them. The paint on the wall looks brighter, but that’s no guarantee that whatever that whatever Flowey did worked.

Sans walks into the Lab. Flowey burrows into his sleeve, wanting to keep a low profile.

The inside of the Lab is completely transformed from the last time Sans saw it. Alphys’ wall of cameras is gone. Instead, the front room of the lab has more of an office feel, with a receptionist typing away at a desk, a burly security guard keeping an eye on everything.

“Sans? Is that you?” The receptionist, a perky cat monster, calls out to him.

“Uh, yup. That’s me.”

“It’s been so long!”

“Y-Yes, it has.”

“Goodness, have you gotten taller since I last saw you? And what a unique outfit you have!”

Her cheery personality is baffling. Why is she being so nice to him? What’s her angle?

“Erm. Thanks.”

“Oh! Here I am, going on and on when you’ve got some other business to get to, I’m sure.”

She waves him to one of the elevators.

“When your brother came in this morning he mentioned he’d be on the third basement level, if I’m not mistaken.”

Sans’ soul gives a stab of hope. His brother is _here_.

He gives the receptionist a jerky nod that could be taken as thanks before he enters the elevator. He’s alone for the ride, so he takes the private moment to question his companion.

“Why was she so nice?”

“Maybe she’s just a nice person. They do exist, you know.”

Sans scoffs, but has to bite back a retort as they reach the third basement level. He’s surprised at the flurry of activity around the Lab, the sheer number of personnel. Did Alphys just fire everyone when she became Royal Scientist?

He wanders the hallways, not sure where he’s supposed to be going. A hand taps his shoulder and he whirls around, ready to fight, magic sparking at the ends of his fingertips. But the monster who surprised him backs up, hands raised in surrender.

“Whoa there! Someone’s jumpy.”

“What do you want?”

The monster gives a short laugh, and scratches the back of his neck sheepishly. “You’re Papyrus’ brother, aren’t you? I can see the resemblance!”

Sans forces his magic to dissipate. None of these monsters are even trying to appear threatening. He’s almost not sure if this is the past, or another world altogether.

“Do you know where he is?”

The scientist eagerly rattles off directions, and even offers to accompany him. Sans declines the offer, the monster’s cheer disconcerting.

Sans follows his directions, and soon finds himself before a door. He enters a bit too eagerly, desperate to see his brother after going so long without him.

The room is a small office. Papyrus is bent over a desk, scribbling in a notebook and muttering to himself. He looks up as Sans enters. It’s hard to tell which brother is more surprised by the other.

The crack on Papyrus’ face is absent, and on the whole he looks smaller, softer. The impressive armor replaced with a flimsy lab coat. And, perhaps most surprisingly, the intimidating glow of red is absent from his eye sockets. He looks…happy. Like the rest of the monsters here.

Papyrus sets down his pen and comes over to him.

“Brother! How did you get here so soon? Father just left to fetch you from the house.” He scrunches up his face. “And in such dark clothes! And what’s this?” Papyrus tugs at the fabric of his scarf, which matches the one around his own neck. “You made yourself a scarf, to match mine? Brother, that’s so sweet.”

Sans grabs Papyrus in a tight hug. Part of him expects to be struck for this, even here. But Papyrus only returns the hug, with a huge amount of enthusiasm.

Sans is the first to pull away, sheepish. “Sorry, Boss, I just—”

“Boss? Are you feeling okay?” Papyrus presses the back of his hand to Sans’ forehead.

Sans bats away his brother’s hand. “Forget it, just. I need you to tell me everything about the project you’re working on. The one about the barrier.”

Papyrus’ eyes shift to the side, and he utters a bald-faced lie.

“I don’t know what you’re talking about.”

“Please, I need to know.”

Papyrus is already starting to crumble. What Sans would give for his Papyrus to see how weak-willed his past self is.

Papyrus wrings his hands. “Father said I wasn’t supposed to tell you.”

“ _Papyrus_.” He musters up his most pathetic expression.

Papyrus reaches out, squeezing his face between his hands.

“Alright! I’ll tell you! Just stop making that face at me!”

Papyrus leads him from the room and through a series of twisted hallways. The chatter and hum of activity from the other scientists drops down to nothing; this is a far more isolated section of the lab. Papyrus brings him into a workshop, in the middle of which is a strange machine. Sans walks closer to it, amazed at its multitude of dials and knobs, but something about the device fills him with a sort of nervous tension.

“What is this supposed to do? Is it a time machine?” The notes had had something to do with time.

“...Not exactly, no. It’s, um. How to explain.” Papyrus taps his foot. “You are familiar with video games, yes, brother? This machine basically lets someone see the “coding” of this world.”

Sans is chewing through that loaded statement when Flowey reveals himself to Papyrus. The tall skeleton gasps.

“Wowie! Sans, you didn’t say you brought a friend.” Papyrus leans down to get a better look at Flowey, who beams at him.

“Howdy, I’m Flowey.”

“Papyrus!”

Flowey extends a leaf, and Papyrus shakes it with ludicrous seriousness.

“Any friend of Sans’ is a friend of mine.” Papyrus says warmly.

“Papyrus, what you said about the code…” Flowey draws them back to the topic at hand. “I know what you’re talking about.” He swivels to look at Sans. “Whenever I reset, that’s what I see. It looks like strings of white coding.”

“Yes, exactly!” Papyrus nods emphatically. “It’s the coding of our world.”

“So how is that supposed to help with the barrier?” Sans asks.

“Oh, that’s simple! Someone can go into the machine, and find the “code” that makes up the barrier, and erase it! Or, if that doesn’t work…” Papyrus grows more solemn, as if remembering something unpleasant. “The user could always increase their LV to the maximum. That might be enough to smash the barrier.”

“But King Asgore is already LV 20.”

“What?” Papyrus looks aghast, outraged. “King Fluffybuns would never hurt anyone. Brother, you shouldn’t say things like that about others.”

Sans takes a couple steps towards the machine.

“Can we use it now?”

“No!” Papyrus blurts. “No, it’s not calibrated properly yet. I’m not sure what would happen if someone were sent through it as they are now.”

“We can help you fix it.” Says Flowey.

Papyrus is conflicted. “Father doesn’t really want anyone else involved.”

The door suddenly opens, snagging their attention.

“Fuck.” Sans swears softly.

Standing in the doorway is a tall skeleton he’s never seen before, but next to him—he sees that sweaty fucker every time he looks in a mirror.

Papyrus glances between the two Sans’, in a way that would be comical in any other circumstance but this one.

The other Sans takes a halting step backwards, looking up at the tall skeleton for assurance.

“Dad? What’s going on?”

“You’ve gotta be fucking with me.” Sans stabs a finger towards the tall skeleton. “I’ve never seen this guy before in my life.”

“Sans, that’s our _father_.” Papyrus stresses. “How can you not—?”

“That’s enough, Papyrus.” The steel in this skeleton’s voice reminds Sans strikingly of his own Papyrus. The monster approaches him, coming close enough for Sans to read the metal nametag clipped to his lab coat—W.D. Gaster.

Gaster stares down at him, but Sans glares up at him in challenge.

“Hello, sir.” Flowey tries to break the tension that runs thick between them. “We’ve come here to help you.”

“Have you now?”

“I know it sounds odd, but Sans and I have traveled back from the future to help you.”

“The future?” Squeaks Papyrus.

“We want to help you breech the barrier.” Flowey throws on all the charm, but Gaster doesn’t crack a smile.

Sans shrugs. “What he said.”

Gaster stares at them for a moment more, then gestures to the machine behind them. “Perhaps you can assist with the finishing touches to the machine.”

Sans doesn’t trust this guy, his supposed father. Everyone else in the past is nice to a fault, but Sans can sense that, beneath this monster’s gentlemanly poise, there’s a mighty cruel soul.

“Anything to help.” Sans says. He turns his back on Gaster, walking over to the machine.

Papyrus grasps, and that’s all he needs—Sans teleports to the side of the room.

Gaster had tried to stab him with a bit of bone magic, the end sharpened to a deadly point.

“Yeah, if you wanna kill me, you’ll have to do better than that.”

Gaster is unperturbed. “Sans would never have dodged.”

“From the future, remember? I’m not your Sans. I’d never fall for such a basic trick.”

“Father, he’s trying to help!” Papyrus beseeches Gaster. “He hasn’t done anything wrong.”

“If this monster truly is Sans, and he truly is from the future,” Gaster summons eight blasters, as both his sons look on from opposite ends of the room, frightened. “Then he has come here to kill me.”

“You know, that wasn’t really on my docket—”

“Sans, please don’t—” Flowey squeezes his arm faintly.

“—but the way I see it, I’ve no choice but to defend myself now.”

Gaster’s blasters encircle Sans. He waits until the beams of energy are firing towards him to teleport behind Gaster. Sans raises his hand, bones shooting up from the ground under Gaster’s feet. To his surprise, Gaster dodges his attack.

“Come now, don’t be so surprised.” The smug bastard smirks at him. “I’d never fall for such a basic trick.”

Now they go at each other in earnest, the room becoming saturated with magical energy as they both launch bone attacks at each other, supplemented by blasters. Neither of them stand still long enough for the other to grab their soul in a blue attack. Amidst the chaos, Sans spots his doppelganger run to the other side of the room, joining Papyrus by the machine. Papyrus looks like he wants to jump in and break up the fight, but the other Sans keeps him there by his side.

Sans hasn’t been hit yet, but he’s getting tired. And he hasn’t even landed a hit on the other monster, so there’s no telling how much HP he has at his disposal.

One of the blasters comes dangerously close to blasting his head off.

“A little help here!” He snaps.

“I—I don’t want to fight!” Flowey insists. “This isn’t why we came back here!”

“At this rate, they’ll be vacuuming our dust off the floor in a couple hours.”

One of Sans’ blasters bites down on the muzzle of one of Gaster’s, but the scientist’s blasters swarm to support their brother, and Sans’ blaster is rapidly overwhelmed.

“God damn it, Flowey!”

Sans is face to face with a blaster when the small monster _finally_ jumps into action. Pellet magic batters and barrages the skull until it’s full of gaping holes. It gives a garbled whine and dissolves.

Gaster redoubles his efforts, and somehow, even with Flowey actively helping, Sans is still at a disadvantage to the other monster. His well of magic drains, and he knows after a few more attacks he’ll be spent. He needs a new plan.

Sans teleports in front of the two brothers. He grabs Papyrus by the wrist and jerks him towards him. Gaster’s onslaught screeches to a halt as Sans places his left hand on Papyrus’ skull.

“You take one step closer and I’m blowing his head off.”

Papyrus whimpers.

The other Sans lunges at him, but Flowey’s vines snake out, restraining him.

“Stop it—don’t hurt him—” The other Sans struggles in vain to free himself from Flowey’s appendages. One would think the guy would trust himself, but no.

Gaster feigns confidence. “You won’t do it. You care for him too much.”

“I’m not your Sans.” Magic builds in his palm. Papyrus tries to put on a brave face, but Sans can feel him trembling. “You don’t know what I feel or what I’m capable of.”

Gaster is paralyzed by indecision for a moment, and that’s all the time Sans needs. He shoves Papyrus out of the way, and pummels Gaster with every last scrap of magic he has in reserve. The scientist, unprepared, finally falls. After all that fuss, Gaster goes away with one direct hit—1 HP, just like him. The bastard dissolves into a pile of dust. Sans hunches over, breathing hard with exertion.

Papyrus makes a small wounded noise and runs to the dust. He crouches down, gathering up some of it in shaking hands. The dust sifts through his fingers.

Flowey must’ve released his captive, because next thing he knows, his double darts in front of him and punches him square across the face.

Sans rubs at his jaw as his other glares at him, tears in his eye sockets.

“The hell was that for? I just did you guys a favor.”

“He was still our dad.”

Papyrus lets out a moan of grief, and the other Sans abandons glaring daggers at him in favor of going over to comfort Papyrus. Sans watches the two of them draw comfort from each other with envy.

“I should reset.” Says Flowey. The little thing is actually crying over what they’ve done, tears splattering onto the tile belowl. “This wasn’t what was supposed to happen.”

“Don’t you fucking dare.” Sans warns him. “I don’t know if I could win against him a second time.”

There’s a sudden cracking sound. A black fissure has appeared in the air, warping the fabric of reality around it.

“What is _that_?”

Several more fissures appear around the room, slowly widening. They have a pull to them; Sans has to grab onto his scarf, lest one of them pull it away.

“Oh no, no, no!” Says Flowey. “Sans, we’ve made a huge mistake. Killing Gaster has seriously messed with the world. It’s starting to collapse.”

“You two!” Sans beckons the brothers over. “Get your asses over here and lend us a hand!”

The brothers approach, wary and frightened.

“What do you want from us?” Says the other Sans.

“Send us through the machine. We have to fix the code before it gets damaged any further.”

“But it’s not safe yet.” Papyrus insists. “I told you, some of the calibrations are off because I—”

Another crack rips into their reality. All of them grab onto the machine, lest they be sucked in by it.

“There’s no time, damn it! Just put us through!”

Sans tries to pry open the glass door himself, but there’s not enough of a groove between the edge of the door and the casing for him wriggle his fingers under it.

“But—”

“Papyrus, do it.” The other Sans insists. “You’re the only one who knows how to activate it.”

Papyrus bends to his brother’s will. He keys in a code, and the hatch swings open. Sans clambers inside, Flowey still wound around his arm.

The door shuts again, and Sans can’t help but feel claustrophobic in the tight space.

The other Sans urges his brother on as he runs through the activation process of the machine.

“I-It’s ready!” Papyrus can barely be heard through the roaring winds.

“Do it!” Says Sans.

Papyrus flicks a final switch.

Darkness starts to creep at the edge of Sans’ vision, and then he feels something start to go wrong. The machine feels like its weighing down his body, trying to flatten him into nothingness. He howls as the bones of his face split. Flowey drops from his arm, no longer able to support himself, wailing at the bottom of the tube. Sans’ legs melt into a puddle of sludge, and he gets one last look at the brothers’ horrified faces before—

~*~

Like the last time he traveled this way with Flowey, everything is dark. But unlike last time, he can move freely. He feels weightless, floating rather than walking through the void.

He sees something—a spark of white light in the distance. He runs towards it.

He gapes as he reaches the light source. It’s lines of code, rows and rows of numbers and figures that make up the building blocks of the world.

“Flowey, where are you?” This is too much to handle on his own.

The flower monster doesn’t appear or announce himself, but instead a translucent screen pops up in front of Sans. It lists the flower’s stats, impressive for a monster so small, but nothing on a boss monster’s level. Beneath his stats are lines and lines of code, presumably all about Flowey.

“Do I have one of these too?”

The file on Flowey blips out of existence. In front of him now instead is a report on himself.

SANS LV 2 HP 1 AT 1 DF 1

Yeah, nothing out of the ordinary there. He scrolls further down, to the lines of code, but pauses. After a chunk of code, there’s a huge portion that looks jumbled and distorted. He touches the glitching patch, and another menu pops up in front of him.

RESTORE DATA?        YES      NO

Sans selects yes, and as the data unscrambles, his mind floods with memories that were long locked away.

His childhood. His love for star-gazing. Him and Papyrus, playing in Waterfall when they were suddenly attack, Sans levelling up. Papyrus’ distancing and growth, his failed teleportation, being forced into the machine by Gaster, Gaster, _Gaster_.

“So you’ve undone the block.” Comes an oily voice from behind.

Sans turns. Gaster stands before him. He looks different. His lab coat has been replaced with a sleek black robe. Four additional hands float around his body, as if he’s trying to imitate a deity. This is Gaster as he idealizes himself.

And clenched in one of his many hands is Flowey, defeated, wilting, but thankfully not yet dead.

“You’re the one responsible for all of this.” Sans’ voice trembles with emotion. “You deliberately messed with the code to alter the world to be how you wanted it.”

“Don’t act as if I’m the sole being to blame.”

Gaster waves his hand, and some of the code reassembles to show moments in time, thousands of instances of cruelty.

“This is who monsters really are. I might have given them the impulse, but it was they who chose to act upon it. There is potential for cruelty in every living creature. Look at how your dear brother treated you after a slight alteration to his code.”

“I’m going to fix this.” Sans’ magic flares up. Blue, as it’s supposed to be. “I’m going to get rid of you for good.”

“You’re nothing but a disappointment and a disgrace.” Gaster snarls. “My only regret is that I had not rid myself of you sooner.”

Though Sans can somewhat meddle with the code, Gaster is firmly entrenched in it and manipulates it smoothly. Every time Sans tries to attack, Gaster alters his file, draining his MP to zero. Sans will take a few steps towards him, only for time to skip and he’s right back where he started. Despite his rage and righteousness, doubt starts to flicker in his soul.

Gaster laughs. “Just give up. It’s all you’re capable of.”

His father drives an attack through his fragile soul. Sans feels it crack in half.

But he won’t give up.

Sans’ soul rejoins in his chest. For Flowey, for Papyrus—for himself—he will not give up.

“Obstinate to the end.” Gaster destroys his soul again. But Sans pulls himself back together. He won’t give up.

Shattered.

Repaired.

Broken.

Mended.

Ruined.

Fixed.

Gaster and Sans continue this deadly duel, neither backing down.

Out of the corner of his eye, Sans spots Flowey stirring into consciousness again. Slowly, to not draw attention to himself, he extends a thin vine, heading for the wall of code.

“Why are you so full of hate?” Sans asks. “You, me, Papyrus—we could’ve been—”

“What? One big, happy family? Do you honestly believe it was possible?”

“Before that day in Waterfall, we were—we were—happy. Why can’t we go back to that?”

“Idiot. Did you think those aggressive monsters just happened to appear that day? I arranged everything. I wanted to see what would happen, I _wanted_ you to increase your LV.” Gaster stares down at him. “I also wanted your stats to increase, but we both know how that turned out. After that, there was little point in the “gentle father” act.”

Flowey’s almost there. Just a little longer. Sans’ soul glows brighter.

“But Papyrus loved you. _I_ loved you.”

“Such empty sentiment is what doomed our forefathers, is why the scraps of our proud kingdom were pushed below the dirt to suffocate.”

Flowey has pulled up a panel.

“Monsterkind must _fight_ to survive. I am the only one who understands this. Only I can save everyone!”

Gaster’s magical energy plunges down to nothing, his 666666 HP drained to 1.

Sans keeps his father pinned by his soul with blue magic.

Flowey pulls himself from Gaster’s suddenly-slack grasp to rejoin Sans.

“What—how—”

Gaster struggles under the effects of Sans’ magic, but cannot shake free. He screams with animalistic frustration.

Sans holds his hand out, palm open.

“You probably don’t believe me, but. I am sorry about this.”

“If you do this, you’ll die too—”

Sans clenches his hand into a fist, and his magical pressure shatters Gaster’s soul.

Gaster lets out a final wail of despair, and vanishes.

Not even his dust is left behind.

Flowey tries to call up Gaster’s file, but the code presents him with nothing.  He smiles up at Sans, weary but happy.

“He’s gone. He’s really gone.”

The code shudders, things shifting and rearranging as Gaster’s absence is felt.

Sans reaches out and calls forth his and Papyrus’ data. He brings both their kill counts down to 0, their levels down to 1. This is what they would’ve been, what they should’ve had.

Data on other monsters rearranges as well, everything returning to what it was supposed to be before Gaster interfered.

Sans can feel his memories shifting, dropping away and being replaced.

This is the end for him. For his brother, for everyone he ever knew. The monsters that will emerge in their place will be correct, will be better—but the monsters Sans knew will be gone forever.

Sans cradles Flowey in his hands as the code whirls around them.

“Everything’s going to change now.” Says Flowey, softly.

“It’ll be alright. This is what we wanted.”

“Sans, I’m scared.”

“Me too.” Sans holds his friend close. “Me too.”

Sans’ world fades to

w          h          i           t           e          .           .           .


	6. Parallel

Snow crunches under his slippers as Sans walks home from his sentry station. He could take one of his shortcuts and be there in an instant, but today he elects to take the scenic route home. He breathes deep, enjoying the scents of snow and pine. In a way, walking home is its own form of procrastination.

He meanders through the woods, waving to the monsters he passes by on the way. Lesser Dog is working at his sentry station. Well, working is a rather loose term for it. The pup is in front of his station, doing his best to sculpt a snow dog.

Sans pauses for a moment, watching the other monster enthusiastically pile up the snow. He builds up the neck three feet too high, and the whole thing crumbles over in a pile. It looks more like a snow sans now, just missing the usual ketchupy signature.

Lesser Dog whines, but quickly recovers, bounding a few feet away to begin the process over again with a fresh batch of snow. Sans smiles at the image and moves on. He’s glad they moved here from New Home. The city was crowded with irascible monsters, always in a hurry. It didn’t gel with Sans’ lifestyle at all. Even Papyrus, the antithesis of lazy, liked to spend time chatting with the grocery store clerk or the mailman. In Snowdin they can fritter time away with such pleasant chatter as they couldn’t before.

Sans crosses over the meticulously painted bridge, and is nearly into town when he spots his brother stampeding towards him.

“Brother!” Papyrus’ enthusiastic shout rings through the trees. It’s a testament to how fit he is that he’s not even panting slightly by the time he reaches Sans.

Sans stuffs his hands in his pockets and looks up at Papyrus. He’s wearing one of his fluffy sweaters today, with a cute little duck stitched into the center.

“Sup, bro?”

“It is an emergency! An emergency of cataclysmic proportions!”

“Oh yeah?” There’s a lightness to Papyrus’ tone that belies his words.

Papyrus bends down to whisper by the side of Sans’ skull, as if this is some big secret. “Undyne is looking for more monsters to join the royal guard.”

“Ok.”

“Sans, a little more enthusiasm would be appreciated. This is my chance! I’ll finally prove to Undyne that I’m not—I’m not—” Papyrus falters. “That I am royal guard material.”

“Of course you are. You’re the coolest guy I know.”

Papyrus puffs out his chest. The gentle breeze tugs at his scarf, and its flares out dramatically behind him.

“Nyeh heh heh! Truer words have never been spoken. But we must make Undyne realize this truth as well.” Papyrus points to him. “This means that you and I will be practicing.”

“Eh, I don’t really wanna join the guard. Sorry, bro.”

“No, brother.” Papyrus sighs. “I need _you_ to train _me_.”

“But you already have lessons with Undyne, don’t you?”

“I need to impress and surprise her if I want to get in, which I can’t do by only training with her.”

“Why not one of the dogs? They’d be willing to help.”

Papyrus taps his gloved hands together. “Even though they are royal guards, I somehow feel like my magic would be too distracting for them.”

He has a good point there. Dogs do love bones.

“It has to be you, Sans.” Papyrus’ zeal ebbs for a moment, face twisting with uncertainty. “I mean, if you want to. I won’t force you to if you really don’t want to.”

Sans elbows him in the side, wanting his smile back. “Aw, Pap. I was just _ribbing_ you. Of course I will; I’m lazy, but I’m not _that_ lazy.”

Papyrus scoops him up in a bone-crushing hug.

“Yes! Thank you!”

Papyrus sets him back down, and levels a lukewarm glare at him.

“Don’t think I didn’t notice that pun.”

“Did you like it?”

“It was far from…humerus.”

Sans snickers, and Papyrus emits a few ‘nyehs’.

“Okay, enough boondoggling. Let us go train!” Papyrus marches with purpose towards the bridge.

“Wait—now?”

Papyrus glances back at him with exasperation. “Yes, now! I only have a week until tryouts! There’s no time to lose!”

Well, it’s not like he can back out now. Sans follows after his brother, back out into the woods. They pause momentarily by Lesser Dog’s station. Papyrus gives the monster a few friendly pats on the head. Lesser Dog’s tail wags furiously. Sans chuckles as he surveys the scenery. It has hardly been ten minutes since he passed through here, but already there are three new mounds of snow. Incredible.

Sans and Papyrus continue on until they reach a quiet clearing, isolated enough that they don’t have to worry about anyone accidentally coming into the range of fire.

“So how do you want to do this?”

“Hmm. When I spar with Undyne, she usually just hurls spears and boulders at me until I give up.”

“Yeah, can’t say that’s really my style.” For him, the less energy he expends, the better. “Why don’t you attack first?”

If this were any other monster, Sans would be nervous. A 1 HP monster has good reason to be leery of combat. But he knows his brother would never hurt him.

“Alright. Brace yourself!” Papyrus’ magical energy surges forth, bright and strong.

His first few attacks are simple, easy to dodge. He’s considerate, letting Sans warm up a bit before he launches into more complex attacks. It’s not necessary, but Sans appreciates the gesture.

Papyrus grows serious, more focused, as he gets into the training session. He keeps Sans constantly on his feet, darting to and fro. Papyrus anticipates where Sans is about to dodge to next and hurls bone attacks there. Eventually Sans gets tangled up in his own feet and ends up face-planting into the snow. The magical attacks heading his way dissipate, harmless crumbs of magic dusting over Sans’ skull.

“Are you alright?”

Sans gives his brother a thumbs up as he picks himself up, shaking the snow free from his clothes.

“Not bad.” Sans says, still panting from the exertion. “I guess it’s my turn.”

Papyrus waits patiently for him to catch his breath. Sans doesn’t disappoint, summoning forth all four of his blasters. They take turns firing at Papyrus, and Sans throws some normal attacks in as well to keep Papyrus guessing.

“Brother! Stop holding back!” Papyrus shouts to be heard over the blaster fire.

Sans realizes he has been holding back some after all, instinctually. He speeds up his attacks, and it isn’t long before one of the manages to make contact. A bone attack glances off Papyrus’ arm, taking some HP with it.

Papyrus yelps, and Sans chokes of his magic as quick as he can. He might not have Papyrus’ ironclad control, but he’s not too bad himself. He recalls his blasters and approaches his brother.

“You okay?”

Papyrus rubs at the wounded area, the fabric of his sweater charred and torn, but he doesn’t seem too pained.

“It just nicked me. I’ll be alright.”

“Still, we should probably call it quits for now.” It’s getting late.

Papyrus pouts, but the pause in the fight lets their bodies linger on how tired they are.

“Very well.”

Papyrus stands and starts to head back. Sans moves to follow, but is struck by a wave of dizziness. Head buzzing, he lists to the side, catching himself on a tree. Papyrus crouches down before him, concerned.

“Head rush.” Sans explains, hoping to quell his brother’s anxiety. “’m fine.”

“You are evidently _not_ fine if one day of training leaves you so exhausted. What will you do when a human falls down here?”

Sans shrugs. “Hide, probably.”

Papyrus groans with fond exasperation. “Clearly we both need training.”

Next thing Sans knows, his brother is carefully picking him up.

“Uh, bro?” Sans clutches the fabric of Papyrus’ shirt so he doesn’t fall. “What are you doing?”

“Nyeh heh heh! Carrying you, of course.” Papyrus begins walking swiftly through the forest, back to civilization.

“You really don’t have to.”

“Nonsense, dear brother.” Papyrus’ tone brooks no argument, so Sans lets himself be carried. Papyrus hums a gentle tune as he walks.

When they’re near the border of Snowdin Sans wriggles a bit.

“You can put me down now.”

Papyrus obliges, figuring Sans would be embarrassed if the town’s residents saw him being carried like a baby bones.

 They walk through town, in comfortable silence.

The closer they get to home though, Papyrus seems to be steeling himself for something. They’re almost there when Papyrus stops short. Sans stops as well, of course.

Papyrus takes a deep breath, and speaks with solemnity.

“As thanks for today, I’ve decided that I will treat you to…Grillby’s.”

Papyrus gestures to the bar they’re standing in front of.

Sans looks at his brother with stars in his eyes. “Bro. Bro, I can’t believe it.” He sniffles, even managing some crocodile tears. The boxy robot on TV might have some real competition here. “You, willingly going to Grillby’s. I thought this day would never come.”

His brother rolls his eyes. “Ugh, enough lollygagging. Let’s go in before I change my mind.”

Papyrus takes a deep breath, and enters the bar like a monster going up to the chopping block.

Most of the usuals are inside, and raise their glasses or holler a greeting as the skeleton brothers enter the establishment.

Papyrus makes a bee line for the bar counter, and swiftly orders for both of them. Despite his loathing for the place, of course he knows Sans’ order without having to be told. Sans hangs back, exchanging idle chatter with the other patrons. Papyrus soon returns with a steaming bag of food in one hand, and a milkshake in the other. Though Sans would’ve preferred to stay and socialize more, both of them are really too exhausted, so they return to their house.

They forgo the kitchen table, eating on the couch before the television set. They both make quite the mess, crumbs spewing everywhere, but Papyrus is content to leave it for morning this time. They watch a new episode of Mettaton’s game show. It’s modeled after humans’ jeopardy, but with five times the chainsaws. Sans guesses wrong every time, but Papyrus accurately calls out an entire category. Who knew Papyrus was so knowledgeable about tea cups.

Hours pass by, and soon enough Papyrus is yawning into his glove. Sans scoots off the couch, disturbing some of the crumbs.

“Time for bed.” He stretches, cracking and popping his joints. Scandalized, Papyrus claps his hands to, well, where his ears _would_ be if he wasn’t a skeleton.

Papyrus switches the television set off and they go upstairs. Papyrus cuddles into his race car bed while Sans searches through his brother’s bookshelf. He picks out one of the fairytales. Papyrus listens with rapt attention until he’s suddenly not, snoring softly. With a fond smile, Sans readjusts his brother’s blankets and returns to his own room to sleep.

~*~

Guard tryouts or no, neither of them can shirk their job responsibilities. After a quick breakfast Papyrus darts off to his Snowdin sentry station, whilst Sans shuffles to his post on the edge of Waterfall.

He settles down onto his stool and pulls out a book of crosswords to occupy his time. Sans flips through the first few pages—Papyrus has scrawled z’s into all the boxes—until he finds a blank sheet. He works through the crossword for a time, until frustration spawned from boredom makes him set it aside.

No humans have fallen into the underground in years, so the job of a sentry has evolved into giving directions to lost tourists, and napping. Unless one was Papyrus, who Sans knows sits dutifully at his guard station in anticipation of a human’s arrival, plotting worthy puzzles for them.

Sans looks around. Waterfall is quiet today, everything slow and languid in the humid heat. So Sans places an “out to lunch” sign on his station and teleports further into Waterfall, before Undyne’s house. As he approaches the door, he hears her playing piano from the other side. He raps twice, loud enough to be heard over the music. Sans then rapidly steps several feet away from the door. Previous experiences have driven the importance of this into him. There’s the sound of thudding footsteps, and then Undyne slams open her door.

“Who’s there?” She spots Sans, and frowns. “Shouldn’t you be at work right now?”

“There’s something I’ve gotta talk with you about.”

She must be able to sense that this isn’t a casual visit, because she only nods and lets him inside.

After closing the door, she goes over to the kitchen. She pours water into a kettle, and glances over her shoulder back at Sans, who takes a seat at the table.

“You want some tea?”

He shrugs, ambivalent. Undyne takes that as a yes, and brings over two mugs. It’s not really his thing, but Sans isn’t a rude guest. He sips at the yellow flower tea. Undyne watches him, waiting for him to speak.

“So. Royal guard tryouts.”

Undyne’s fins droop some, as if regretful.

“Yes. A few monsters recently retired, and—it was Asgore’s idea.”

His grip tightens on his tea cup. He looks away from her, feeling uncomfortable and awkward.

“Undyne—” He doesn’t know how to say it. Papyrus becoming a royal guard would lead to a lot of things Sans isn’t ready for. Hell, it would lead to a lot of things _Papyrus_ isn’t ready for.

He feels stuck between two opposing sides of himself, one which wants to help his brother reach his goals, and the other which wants to keep the status quo.

Thankfully, Undyne realizes what Sans wants to tell her without him fumbling out an incoherent explanation.

“You don’t have to worry about it.” She promises him. “He’ll…He’ll stay right where he is.”

Sans lets out a breath he didn’t know he was holding. “Good. That’s good.”

They both pause a moment to drink their tea. Tastes like shame and betrayal.

“He’ll want a reason.” Undyne blurts, her sudden loud volume making Sans nearly drop his tea in surprise. “He’ll want to know why, Sans. What am I supposed to tell him?”

“….Special training.”

“What?” She leans closer, intrigued.

“Special training for the royal guard, but. Involving anything else.” He gestures towards her baby grand. “I would say piano lessons, but skeletons aren’t really equipped with strong fingers.”

“That’s it!” Undyne slams her fists on the table to emphasize her epiphany. Sans is able to catch his cup, but Undyne’s tips over on its side; thankfully, it’s empty. “Papyrus likes to cook, right? What’s his favorite food?”

“Spaghetti.” Says Sans, immediately.

“Are you sure?”

“Pasta-tive.”

“That was awful, and you know it.”

Sans winks at the captain. “If I had a _penne_ for every time I heard that…”

“Out!” Undyne bellows. She points to the door. “Get out of my house and get your butt to work!”

Sans holds up his hands in a gesture of surrender and backs up, towards the door.

“Alright, alright, I’m going.”

He’s turning the doorknob when she speaks up again.

“I really mean it, Sans. You don’t have to worry so much. You’re not the only one keeping an eye out for him.”

He could make a pun about her eye, but he’s not devoid of tact or gratitude. He just lets her words hang between them for a moment, showing he’s acknowledged them, then leaves her house.       

On his way back to his sentry station, Sans notices a door he’s never seen before. The door is gray, washed out; discordant with its surroundings.

Giving in to his curiosity, Sans grabs the doorknob and opens the door. Beyond is a small, white room.

“Hello?” He calls out. His voice reverberates throughout the small space. No one responds.

Sans steps into the peculiar little room, scouring it for something, anything. It’s nothing but a white box.

He feels a sudden presence behind him, like someone breathing down his neck. He whips around, but nothing’s there.

Sans leaves the room, and when he shuts the door again, the whole thing vanishes. Sans taps at the wall, trying to find the door again, but it’s gone. Like it was never there. Is this some elaborate prank by another monster?

Sans shrugs it off. What else can he do?

~*~

A week passes. Papyrus tries out for the guard, and the bad news is broken to him on the message board in town. Sans quickly steers his brother back to their house before he erupts into tears.

“Nyoo hoo hoo.” Papyrus sniffles. He sits, curled up on the couch in their coziest blanket. He dabs a tissue at his eye socket. The box is on the couch next to him; he’s already gone through about half of it, bunched up, used tissues scattered all around him.

Sans returns to his brother’s side from the kitchen, offering him a mug of hot chocolate. With milk, of course.

Papyrus sips at it miserably.

“I’m sorry, Pap.” He hates seeing his brother like this, but there’s no denying the small pulse of relief in his soul.

“I don’t understand what I did wrong.” Says Papyrus. “I trained really hard.”

They had. Sans has never felt this sore before in his entire life.

“You should give Undyne a call. I’m sure she’ll tell you her reasoning.”

Papyrus mumbles something, too low for Sans to hear.

“What?”

“…I’m afraid to.”

“Why? She’s your friend. She—She’ll be honest with you.”

“That’s just it!” The hand Papyrus isn’t using to hold the mug fiddles anxiously with the fabric of the blanket. “If I call her up, she’ll tell me how bad of a fighter I am—how she was never really my friend, was just pretending—”

“Whoa, bro.” He was not prepared for this. This slight has peeled back Papyrus’ skin of confidence, exposing his raw insecurities.

“I think you might be overthinking this.”

“You think?”

“I think.”

Papyrus grabs another fistful of tissues and wipes at his face, tears still streaming.

“Just call her.” Says Sans. “It’ll be fine. And even if it’s not—you have me, Pap. You’ve always got me.”

“Aw.” His heartfelt words have perked Papyrus up a bit. He sets down the mug, and digs out his phone from his pocket.

Papyrus keys in Undyne’s number, but then hesitates over the call button. He glances at Sans, who nods at him reassuringly. He presses it, and it only rings once before Undyne picks up; she must’ve been glued to her phone, awaiting the call.

“H-Hello? Undyne?” He squeaks out.

Undyne shouts loudly enough through the receiver that Sans can hear everything. Papyrus’ timidity quickly vanishes, as Undyne explains that she wanted to bring him to the next level of training—advanced, special training. When she was finished with him, he wouldn’t just be a royal guard, but her protégé, perhaps even her second-in-command.

Papyrus’ eyes sparkle at the thought. Hey, they all need dreams to strive for.

The second Undyne hangs up, Papyrus tackles Sans in a hug.

“Special training, brother! Special training!”

Sans returns the hug affectionately. “See? It all worked out.”

Papyrus hugs him tighter, and Sans knows everything’s going to be okay.

**Notes for the Chapter:**

> And we're done! I have more Undertale fics planned for the future, so keep an eye out.


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